Acronyms

The railway is full of acronyms. The following list of acronyms was released by Network Rail on 10th August 2018 from a data set held in TOPS, hence all text is in upper-case.

The data has not been updated for many years and may not reflect current practice - caveat lector.

Acronym	Meaning
ALERT	PROVIDE CONDUCTOR BETWEEN POINTS NAMED FOR GUARD OF .......
BYRAG	THE FOLLOWING TRAFFIC MAY BE ACCEPTED BY ARRANGEMENT ONLY.
CAPE	UNDERMENTIONED TRAINS WILL NOT RUN. ADVISE ALL CONCERNED.
CICERO	SPECIAL TRAINS WILL RUN AS UNDER. ADVISE ALL CONCERNED.
CREOLE	ARRANGE TO WORK FORWARD.
DAGGER	UNTIL THE ASSENT OF ........... IS OBTAINED.
EGER	PROVIDE CONDUCTOR BETWEEN POINTS NAMED FOR DRIVER OF ......
FOCUS	ARRANGE TO STRENGTHEN THE UNDERMENTIONED TRAIN(S) SHOWN.
GOOSE	STOP ACCEPTING FOLLOWING UNTIL FURTHER NOTICE.
GOSLING	CEASE FORWARDING THE FOLLOWING UNTIL FURTHER NOTICE.
HUMPEX	WAGON OR LOADS NOT TO PASS OVER SHUNTING HUMPS.
NOTCH	CANNOT ACCEPT OWING TO .........
PINE	TRAIN(S) AS UNDER TERMINATE(D) SHORT OF DESTINATION.
RESPAC	RESUME ACCEPTANCE OF TRAFFIC IN STRICTLY NORMAL QUANTITIES FOR;
RESPOND	YOU MAY RESUME FORWARDING FOLLOWING.
SHUNTEX	NOT TO BE LOOSE SHUNTED OVER A HUMP OR ALONG THE FLAT.
SKUNK	SECURE CONNECTION WITH ......
SLASH	STOP ACCEPTING UNTIL FURTHER ADVISED COAL & COKE TO .......
SPATE	TRAINS BETWEEN FOLLOWING POINTS MAY RUN AT ORDINARY SPEED ON AND AFTER DATE NAMED. WITHDRAW RESTRICTION.
SPEDWAY	SPEED OF TRAINS REQUIRED TO BE REDUCED TO UNDERMENTIONED MILES PER HOUR BETWEEN FOLLOWING POINTS ON AND AFTER DATE NAMED. ARRANGE AND REPLY.
THROSTLE	KEEP ON HAND FOR MY ORDER.
TURBOT	BE PREPARED TO DEAL WITH FOLLOWING ON UNDERMENTIONED TRAIN.
URE	IT IS IMPORTANT FOR FOLLOWING REASON THAT UNDERMENTIONED TRAIN SHOULD BE WORKED PUNCTUALLY. DO ALL THAT IS NECESSARY, SO FAR AS YOU ARE CONCERNED.
WING	FOLLOWING STILL COMING FORWARD. MAKE STOP EFFECTIVE AT ONCE.
A&D BOOK	ARRIVAL AND DEPARTURE BOOK.
A&DG	ARCHITECTURE AND DESIGN GROUP.
A	AMPERE(S).
AA	AGGREGATION ALLOWANCE.
AAL	ATM ADAPTATION LAYER.
AAMP	ASSIGNED AREA MAINTENANCE POINT.
AARP	APPLETALK ADDRESS RESOLUTION PROTOCOL.
AB	AIR BRAKE.
ABB TRANSPORTATION LTD.	(EX BREL) NOW PART OF ASEA BROWN BOVERI GROUP.
ABC	ANNUAL BUDJETARY CONTROL.
ABC	ATANASOFF-BERRY COMPUTER.
ABCL	AUTOMATIC BARRIER CROSSING LOCALLY MONITORED.
ABEND	ABNORMAL END.
ABI	APPLICATION BINARY INTERFACE.
ABM	ASYNCHRONOUS BALANCED MODE.
ABP	ASSOCIATED BRITISH PORTS.
ABP	AIR BRAKE PIPE.
ABPASS	AUTOMATIC BUSINESS PAY AND SECURITY SYSTEM.
AC	ACCESS CONTROL.
AC	ALTERNATING CURRENT.
ACCT	AUTOMATIC CONTROL CENTRE TOPS/TRUST.
ACD	AUTOMATIC CALL DISTRIBUTION.
ACE	ADVANCED COMPUTING ENVIRONMENT.
ACE	AREA CIVIL ENGINEER.
ACF	ACCESS CONTROL FACILITY.
ACF/NCP	ADVANCED COMMUNICATIONS FUNCTION/NETWORK CONTROL PROGRAM.
ACF/SSP	ADVANCED COMMUNICATIONS FUNCTION/SYSTEM SUPPORT PROGRAM.
ACFM	ADOBE COMPOSITE FONT METERICS.
ACIS	AMERICAN COMMITTEE FOR INTEROPERABLE SYSTEMS.
ACK	ACKNOWLEDGE (ACKNOWLEDGMENT?).
ACL	ADVANCED CMOS LOGIC.
ACLG	AREA COMPUTER LIASON GROUP.
ACM	ASSOCIATION FOR COMPUTING MACHINERY.
ACPDP	ALTERNATING CURRENT PLASMS DISPLAY PANEL.
ACRES	ACCOUNTS RECEIVABLE SYSTEM.
ACS	ADVANCED COMMUNICATIONS SYSTEM.
ACS	ASYNCHRONOUS COMMUNICATIONS SERVER.
ACSE	ASSOCIATION CONTROL SERVICE ELEMENT.
ACTFEL	ALTERNATING CURRENT THIN FILM ELECTROLUMINESCENT.
A/D	ANALOGUE TO DIGITAL CONVERTER.
ACTS	ADVANCED COMMUNICATIONS TECHNOLOGY SATELLITE.
AD	APPLICATION DEVELOPMENT.
ADAPSO	ASSOCIATION OF DATA PROCESSING SERVICE ORGANAISATIONS.
ADB	APPLE DESKTOP BUS.
ADC	AMERICAN DISPLAY CONSORTIUM.
ADC	ANALOGE-TO-DIGITAL CONVERTER.
ADCCP	ADVANCED DATA COMMUNICATION(S?) CONTROL PROCEDURE(S?).
ADD	ADAPTER DEVICE DRIVER.
ADDRESS	ONE OR A GROUP OF CHARACTERS THAT SPECIFIES THE RECIPIENT OR ORIGINATOR OF TRANSMITTED DATA.
ADE	APPLICATION DEVELOPMENT ENVIRONMENT.
ADEX	AWAY DAY EXCURSION.
ADF	APPLICATION DEVELOPMENT FACILITY.
ADMD	ADMINISTRATION MANAGEMENT DOMAIN.
ADI	AUTODESK DEVICE INTERFACE.
ADP	AUTOMATIC DATA PROCESSING.
ADP	ADVANCED DATA PROCESSING.
ADP	ADMINISTRATIVE DATA PROCESSING.
ADPCM	ADAPTIVE DIFFERENTIAL PULSE CODE MODULATION.
ADR	EUROPEAN AGREEMENT CONCERNING THE INTERNATIONAL CARRIAGE OF DANGEROUS GOODS BY ROAD.
ADRS	A DEPARTMENTAL REPORTING SYSTEM.
ADS	APPLICATION DEVELOPMENT SYSTEM.
ADS	AUTOCAD DEVELOPMENT SYSTEM.
ADSP	APPLETALK DATASTREAM PROTOCOL.
ADSR	ATTACK DECAY SUSTAIN RELEASE.
ADT	ABSTRACT DATA TYPE.
AE	APPLICATION EXECUTION.
AEA	AMERICAN ELECTRONICS ASSOCIATION.
AED	ADVANCED ERROR DIFFUSION.
AEGIS	ADVANCED ELECTRONIC GUIDANCE AND INSTRUMENTATION SYSTEM.
AEI	AUTOMATIC EQUIPMENT IDENTIFICATION.
AEP	APPLICATION ENVIRONMENT PROFILE.
AF	AUDIO FREQUENCY.
AFCAC	AIR FORCE COMPUTER AQUISITION CENTER.
AFC	AREA FREIGHT CENTRE.
AFE	APPLE FILE EXCHANGE.
AFFF	AQUEOUS FILM FORMING FOAM (TYPE OF FIRE EXTINGUISHER).
AFI	APPLETALK FILING INTERFACE.
AFII	ASSOCIATION OF FONT INFORMATION INTERCHANGE.
AFIPS	AMERICAN FEDERATION OF INFORMATION PROCESSING SOCIETIES INC.
AFM	ADOBE FONT METRICS.
AFM	AREA FLEET MANAGER.
AFM	AREA FREIGHT MANAGER.
AFP	APPLETALK FILING PROTOCOL.
AFT	ASSISTANCE TO FAILED TRAINS. (EXTRA AIR PIPE ON LOCOMOTIVES)
AFS	ANDREW FILE SYSTEM.
AG	ARCADE GAME.
AGGREGATE	THE TOTAL BANDWIDTH OF A MULTIPLEXED BITSTREAM CHANNEL, EXPRESSED AS BITS PER SECOND.
AHB	AUTOMATIC HALF BARRIER.
AI	ARTIFICIAL INTELLIGENCE.
AI	APPLICATION INTERFACE.
AIFF	AUDIO INTERCHANGE FILE FORMAT.
AIIM	ASSOCIATION FOR INFORMATION AND IMAGE MANAGEMENT.
AIMS	AUTO INDEXING MASS STORAGE.
AIX	ADVANCED INTERACTIVE EXECUTIVE (UNIX).
AL	ANNUAL LEAVE.
ALAP	APPLETALK LAP.
ALC	ASSEMBLY LANGUAGE CODING.
ALCS	AIR-LINE CONTROL SYSTEMS.
ALCS	ALSO USED AS AN ALTERNATIVE NAME FOR CRS
ALGOL	ALGORITHMIC ORIENTED LANGUAGE.
ALGORITHM	A PROCESS OR SET OF RULES NECESSARY FOR A COMPUTER TO PERFORM ITS TASK.
ALM	APPLICATION LOADABLE MODULE.
ALO	AT LEAST ONCE.
ALR	ADVANCED LOGIC RESEARCH INC.
ALU	ARITHMETIC LOGIC UNIT.
AM	AMPLITUDE MODULATION
AMD	ADVANCED MICRO DEVICES, INC.
AMEE	AREA MECHANICAL AND ELECTRICAL ENGINEER.
AMI	ALTERNATE MARK INVERSION.
AMI	AMERICAN MEGATRENDS INC.
AMI	AREA MOVEMENTS INSPECTOR. (SIGNALLING SUPERVISOR)
AMLCD	ACTICE MATRIX LIQID CRYSTAL DISPLAY.
AMOS	AREA MANAGERS OPERATING SYSTEM.
AMPS	AREA MATERIALS PROCESSING SYSTEM.
AMPS	AREA MANAGEMENT PROCUREMENT SYSTEM.
AMS	AUSTENTIE MANGANESE STEEL.
AMT	ADDRESS MAPPING TABLE.
AMT	APPLICATION MANAGERS TOOLKIT.
ANDF	ARCHITECTURE NEUTRAL DISTIBUTED FORMAT.
ANI	AUTOMATIC NUMBER IDENTIFICATION.
ANSI	AMERICAN NATIONAL STANDARDS INSTITUTE.
ANTC	ADVANCED NETWORKING TEST CENTRE.
AOC	AREA OPERATIONS CENTRE.
AOCE	APPLE OPEN COLLABORATION ENVIRONMENT.
AOCL	AUTOMATIC OPEN CROSSING LOCALLY MONITORED.
AOL	AMERICA ONLINE.
AOR	APPLICATION OWNING REGION
AOS	ACADEMIC OPERATING SYSTEM.
APA	ADVANCE RETURN. (NFM)
APA	ALL POINTS ADDRESSABLE.
APC	AUTOMATIC POWER CONTROL.
APCAP	APTIS-CAPRI INTERFACE SYSTEM.
APCUG	ASSOCIATION OF PERSONAL COMPUTER USER GROUPS.
APDA	APPLE PROGRAMMERS AND DEVELOPERS ASSOCIATION.
APEX	ADVANCE PURCHASE EXCURSION.
API	APPLICATION PROGRAMMING INTERFACE.
APL	A PROGRAMMING LANGUAGE.
APM	ADVANCED POWER MANAGEMENT.
APOLS	APTIS-PORTIS ON-LINE SYSTEM.
APP	APPLICATIONS PORTABILITY PROFILE.
APPC	ADVANCED PROGRAM-TO-PROGRAM COMMUNICATIONS.
APPN	ADVANCED PEER-TO-PEER NETWORKING.
APRIL	APPLICATION RATIONAL INTERFACE LOGIC.
APS	SUPER ADVANCE RETURN. (NFM)
APSE	ADA PROGRAMMING SUPPORT ENVIRONMENT.
APT	ADVANTED PASSENGER TRAIN.
APT	AUTOMATIC PROGRAMMING TOOLS.
APTA	AMERICAN PASSENGER TRANSIT AUTHORITY.
APTIS	ALL PURPOSE TICKET ISSUING SYSTEM.
APX	APEX RETURN. (NFM)
AQ	ACCUMULATOR-QUOTIENT REGISTER.
AR	ADDRESS REGISTER.
ARC	ADVANCED RISC COMPUTING.
ARC	ANGLIA REGION (FORMER).
ARC	FORMERLY: AMEY ROADSTONE CORPORATION.
ARCNET	ATTACHED RESOURSE COMPUTER NETWORK.
ARDIS	ADVANCED NATIONAL RADIO DATA SERVICE.
ARIS	INSURANCE CLAIMS SYSTEM.
ARM	ADVANCED RISC MACHINE.
ARM	ASYNCHRONOUS RESPONSE MODE.
ARP	ADDRESS RESOLUTION PROTOCOL.
ARPA	ADVANCED RESEARCH PROJECTS AGENCY
ARPANET	ADVANCED RESEARCH PROJECTS AGENCY NETWORK.
ARQ	AUTOMATIC REPEAT REQUEST.
ARS	AUTOMATIC ROUTE SETTING.
AS	ADVANCED SERVER (WINDOWS NT).
AS	APPLICATION SYSTEM (AS/400).
AS/400	APPLICATION SYSTEM/400.
ASCII	AMERICAN STANDARD CODE FOR INFORMATION INTERCHANGE.
ASDSP	APPLICATION SPECIFIC DSP.
ASE	APPLIED SERVICE ELEMENTS.
ASIC	APPLICATION-SPECIFIC INTEGRATED CIRCUIT.
ASK	AMPLITUDE SHIFT KEYING.
ASLEF	ASSOCIATED SOCIETY OF LOCOMOTIVE ENGINEERS AND FIREMEN.
ASM	ASSOCIATION FOR SYSTEMS MANAGEMENT.
ASN.1	ABSTRACT SYNTAX NOTATION.1
ASP	ASSOCIATION OF SHAREWARE PROFESSIONALS.
ASPI	ADVANCED SCSI PROGRAMMING INTERFACE.
ASR	ARCHIVE, SEND, RECEIVE (NTN)
ASR(WP)	ARCHIVE, SEND, RECEIVE (WORD PROCESSOR).
ASSP	APPLICATION SPECIFIC STANDARD PART.
ASW	ALLIED STEEL AND WIRE.
ASW	AMENDED STATION WORKING.
AT	ADVANCED TECHNOLOGY.
AT&T	AMERICAN TELEPHONE AND TELEGRAPH.
ATA	ARCNET TRADE ASSOCIATION.
ATB	AIRLINE TICKET AND BOARDING PASS.
ATC	AUTOMATIC TRAIN CONTROL.
ATM	ADOBE TYPE MANAGER.
ATM	ASYNCHRONOUS TRANSFER MODE.
ATM	AUTOMATIC TELLER MACHINE.
ATO	AUTOMATIC TRAIN OPERATION.
ATOMS	ADVANCED TRANS-MANCHE OPERATIONS MANAGEMENT SYSTEM.
ATP	APPLETALK TRANSACTION PROTOCOL.
ATP	AUTOMATIC TRAIN PROTECTION.
ATTA	AUTOMATIC TRACK AND TOP ALIGNMENT.
ATR	AUTOMATIC TRAIN REPORTING.
AUI	AUXILIARY(ACCESS//ATTACHMENT?) UNIT INTERFACE.
AUTO	AUTOMATIC SIGNAL.
AUTODIN	AUTOMATIC DIGITAL NETWORK.
AUTOVON	AUTOMATIC VOICE NETWORK.
AV	ANTI VIRUS.
AVC	AUDIO VIDEO CONNECTION.
AVE	SPANISH HIGH SPEED TRAIN. (PUNTA)
AVACS	AIRE VALLEY CONTROL SYSTEM.
AVI	ADDED VALUE INITIATIVES.
AVI	AUDIO VIDEO INTERFACE (INTERACTIVE?/INTERLEAVED?).
AVI	AUTOMATIC VEHICLE IDENTIFICATION.
AVIS	AIRLINE VOUCHER INFORMATION SYSTEM.
AVR	AUTOMATIC VOLTAGE REGULATOR.
AWL	ABSENT WITHOUT LEAVE.
AWS	AUTOMATIC WARNING SYSTEM.
AXIS	ACCOUNTING & EXPENDITURE INFORMATION SYSTEM.
B	BYTE
BAD	BROKEN AS DESIGNED.
BAL	BASIC ASSEMBLY LANGUAGE.
BAL	BRANCH AND LINK.
BALUN	A TRANSFORMER FOR LEVELLING OUT IMPEDANCE DIFFERENCES.
BANDWIDTH	THE RANGE OF SIGNAL FREQUENCIES THAT CAN BE CARRIED ON A COMMUNICATIONS CHANNEL.
BAR	METRIC AIR PRESSURE MEASUREMENT.
BASIC	BEGINNER'S ALL-PURPOSE SYMBOLIC INSTRUCTION CODE.
BASREC	BRIDGE AND STRUCTURES RECORD SYSTEM.
BATS	BUSINESS ANALYSIS OF TRAIN SERVICES.
BAUD	A UNIT OF SPEED AS APPLIED TO A TELECOMMUNICATIONS LINE.
BBS	BULLETIN BOARD SYSTEM.
BCA	BALANCE CONTROL ACCOUNTS (BOOKING OFFICE 4 WEEKLY REPORT).
BCC	BUREAU CENTRAL DE COMPENSATION.
BCC	BUSINESS CONTROL CENTRE.
BCD	BINARY CODED DECIMAL.
BCDIC	BINARY CODED DECIMAL INTERCHANGE CODE.
BCF	BROMOCHLORODIFLOUROMETHANE (FIRE EXTINGUISHER).
BCP	BRAKE CYLINDER PRESSURE.
BCP	BYTE CONTROLLED PROTOCOLS.
BCPL	BASIC COMBINED PROGRAMMING LANGUAGE.
BCS	BINARY COMPATIBILITY STANDARD.
BCS	BOSTON COMPUTER SOCIETY.
BCS	BRITISH COMPUTER SOCIETY.
BCT	BRAKE CONTINUITY TEST.
BDF	BINARY DISTRIBUTION FORMAT.
BDZ	BULGARIAN STATE RAILWAYS.
BELLCORE	BELL COMMUNICATIONS RESEARCH.
BER	BASIC ENCODING RULES.
BER	BIT ERROR RATE.
BEST	BORLAND ENHANCED SUPPORT AND TRAINING.
BFK	BRAKE FIRST CORRIDOR.
BFT	BINARY FILE TRANSMISSION (TRANSFER?).
BG	BRAKE GANGWAYED.
BGI	BORLAND GRAPHIC INTERFACE.
BH	BULL HEAD RAIL.
BHN	BANK HOLIDAY NOTICE.
BHX	BANK HOLIDAYS EXCEPTED.
BIF	BINARY INITIALIZATION FILE.
BIFF	BINARY INTERCHANGE FILE FORMAT.
BIFS	BASIC INFRASTRUCTURE FACILITIES SYSTEM.
BIJ	BILLET INTERNATIONAL JEUNE (YOUTH TRAVEL).
BIMBO	BUY-IN AND MANNAGEMENT BUY-OUT.
BIOC	BREAK INTO OTHER COMPUTERS.
BIOS	BASIC INPUT-OUTPUT SYSTEM.
BIPS	BILLION INSTRUCTIONS PER SECOND.
BIS	BATTERY ISOLATION SWITCH.
BIS	BUSINESS INFORMATION SYSTEM.
BISDN	BROADBAND ISDN. (B/ISDN?)
BISYNC	BINARY SYNCHRONOUS.
BIT	BINARY DIGIT.
BITNET	BECAUSE IT'S TIME NETWORK.
BITS	BASE INFORMATION TRANSFER SYSTEM.
BITSG	BUSINESS INFORMATION TECHNOLOGY SYSTEMS GROUP.
BIU	BUS INTERACE UNIT.
BIX	BYTE INFORMATION EXCHANGE.
BL	BEREAVEMENT LEAVE.
BL	BRANCH LINE.
BLAST	BLOCKED ASYNCHRONOUS TRANSMISSION.
BLEVE	BOILING LIQUID EXPANDING VAPOUR EXPLOSION.
BLF	BUSY LINE FEED.
BLG	BUSINESS LIASON GROUP.
BLOB	BINARY LARGE OBJECT.
BLS	BERN-LOTSCHBERG-SIMPLON RAILWAY (SWITZERLAND).
BLT	BLOCK TRANSFER.
BMP	BITMAP.
BNC	BAYONET N CONNECTOR.
BNM	BLUE NOISE MASK.
BOBO	LOCO WHEEL ARRANGEMENT: 2X2 (BO-BO)
BOC	BELL OPERATIONG COMPANY.
BOF	BEGINING OF FILE.
BOMP	BILL OF MATERIALS PROCESSOR.
BOP	BIT ORIENTED PROTOCOL.
BOP	BOOKING ON POINT.
BOQ	BILLS OF QUANTITIES.
BOX	SIGNAL BOX.
BPI	BITS PER INCH.
BPOT	BRAKE POST OFFICE STOWAGE.
BPS	BITS PER SECOND.
BRASS	BRITISH RAIL ADDITIONAL SUPERANNUATION SCHEME.
BRC	BRITISH RAIL COMPUTING.
BRCATS	BRITISH RAIL COMPUTER ALLOCATION OF TICKETS TO SERVICES.
BREL	EX BRITISH RAIL ENGINEERING LTD. NOW ABB TRANSPORTATION LTD.
BRF	BUSINESS RESOURCES FORUM.
BRI	BASIC RATE INTERFACE.
BRIEF	BASIC RECONFIGURABLE INTERACTIVE EDITING FACILITY.
BRI	BRITISH RAIL INTERNATIONAL.
BRIMS	BRITISH RAIL INCIDENT MONITORING SYSTEM.
BRIPAS	BRITISH RAIL INTERNATIONAL PASSENGER ACCOUNTING SYSTEM.
BRIS	BRITISH RAIL INFRASTRUCTURE SERVICES.
BRML	BRITISH RAIL MAINTENANCE LIMITED.
BRPB	BRITISH RAIL PROPERTY BOARD.
BRPS	BRITISH RAIL PENSION SCHEME.
BRPTT	BRITISH RAIL PASSENGER TIMETABLE.
BRSA	BRITISH RAIL STAFF ASSOCIATION.
BRS	BIBLIOGRAPHIC RETRIEVAL SERVICE.
BRS	BRITISH RAIL SUPPORT.
BRSF	BRITISH RAILWAYS SUPERANNUATION FUND.
BRT	BRITISH RAIL TELECOMMUNICATIONS LTD.
BRUTE	BRITISH RAIL UNIVERSAL TROLLEY EQUIPMENT.
BS	BRITISH STANDARD.
BSA	BUSINESS SOFTWARE ALLIANCE.
BSA	BRITISH STANDARD ACRONYM.
BSC	BINARY SYNCHRONOUS COMMUNICATIONS.
BSC	BUSINESS SYSTEMS COMPUTING.
BSD	BERKELEY SOFTWARE DISTRIBUTION.
BSI	BERGISCHE STAHL INDUSTRIE (COUPLER USED ON SPRINTERS).
BSI	BRITISH STANDARDS INSTITUTE.
BSK	BRAKE STANDARD CORRIDOR.
BSO	BRAKE STANDARD OPEN.
BSOT	BRAKE STANDARD OPEN - TROLLEY.
BSP	BANK SETTLEMENT PLAN.
BSP	BASIC STATE PENSION.
BSS	BLOCK STARTED BY SYMBOL.
BSS	BRAKE SELECTOR SWITCH.
BSS	BUSINESS SYSTEMS & SERVICES. NOW BUSINESS SYSTEMS.
BST	BRITISH SUMMER TIME.
BT	BRITISH TELECOM.
BT	BODENSEE-TOGGENBURG RAILWAY (SWITZERLAND).
BTAM	BASIC TELECOMMUNICATIONS ACCESS METHOD.
BTC	BRITISH TRANSPORT COMMISSION.
BTL	BELL TELEPHONE LABORATORIES.
BTLZ	BRITISH TELECOM LEMPEL ZIV.
BTP	BRITISH TRANSPORT POLICE.
BTPFSF	BRITISH TRANSPORT POLICE FORCE SUPERANNUATION FUND.
BTS	BUSINESS TRAVEL SERVICE.
BTU	BRITISH THERMAL UNIT.
BWOD	BANDWIDTH ON DEMAND.
BUSSEC	BUSINESS SECTOR CODE.
BX	BASE EXCHANGE.
BYTE	SEQUENCE OF 8 BITS.
C	CELSIUS.
C	CENTRAL (POSITION OF POINTS INDICATOR).
C	A PROGRAMMING LANGUAGE THAT SUCCEEDED BCPL.
C&B	HQ CONTROL AND BOOK KEEPING SYSTEM.
C&T	CHIPS AND TECHNOLOGIES.
C&W	CARRIAGE & WAGON.
CA	COMPUTER ASSOCIATES INTERNATIONAL, INC.
CAC	CENTRAL ARBITRATION COMMITTEE.
CACM	COMMUNICATIONS OF THE ASSOCIATION FOR COMPUTING MACHINERY.
CAD	COMPUTER AIDED DESIGN.
CADD	COMPUTER AIDED DESIGN AND DRAFTING.
CAE	COMPUTER AIDED ENGINEERING.
CAE	COMMON APPLICATIONS ENVIRONMENT.
CAE	COMPUTER APPLICATION ENGINEER.
CAF	CENTRAL ALLOCATION FILE.
CAF	CUSTOM ACCEPTANCE FORM.
CAG	COMPUTER AUDIT GROUP.
CAI	COMPUTER ASSISTED INSTRUCTION.
CAI	CONVERSATIONAL ALGEBRAIC LANGUAGE.
CAI	COMPUTER ASSOCIATES INTERNATIONAL.
CAIS	COMMON ASPE INTERFACE SPECIFICATION.
CAL	CONVERSATIONAL ALGEBRAIC LANGUAGE.
CAL	COMPUTER ASSISTED LEARNING.
CALS	COMPUTER-AIDED ACQUISITION AND LOGISTICS SUPPORT.
CAM	COMMON (CHANNEL?) ACCESS METHOD.
CAM	COMPUTER AIDED MANUFACTURING.
CAM	COMPUTER AIDED MANAGEMENT.
CAM	CONTENT ADDRESSABLE MEMORY.
CAMP	CORPORATE ASSOCIATION FOR MICROCOMPUTER PROFESSIONALS.
CAMPS	COMPUTER ASSISTED MAINTENANCE PLANNING SYSTEM.
CAP	COLUMBIA APPLETALK PACKAGE.
CAPITAL	CONTROL & PLANNING INFORMATION TECHNOLOGY APPLICATIONS LINK.
CAPRI	COMPUTERISED ANALYSIS OF PASSENGER REVENUE INFORMATION.
CAPSL	CANON PRINTING SYSTEM LANGUAGE.
CAR	COMPUTER AIDED (ASSISTED?) RETRIEVAL.
CAR	CONTENTS OF THE ADDRESS PART OF THE REGISTER.
CARDS	CENTRAL ARCHIVE FOR REUSABLE DEFENSE SOFTWARE.
CARMD	CARRIAGE MAINTENANCE DEPOT.
CARS	CORRECTIVE ACTION REQUIREMENTS.
CAS	CENTRAL ADVERTISING SERVICES.
CAS	COMMUNICATING APPLICATIONS SPECIFICATION.
CASE	COMPUTER AIDED SOFTWARE ENGINEERING.
CASE	COMPUTER AIDED SYSTEMS ENGINEERING.
CASH	CASH ACCOUNTING AND RECONCILIATION SYSTEM.
CASSIS	CLASSIFICATION AND SEARCH SUPPORT INFORMATION SYSTEM.
CAT	COMPUTER AIDED TYPESETTING.
CAT	COMPUTER AIDED TOMOGRAPHY.
CATE	COMPUTER ASSISTED TIMETABLE ENQUIRIES.
CATIS	COMMON APPLICATIONS AND TOOLS INTEGRATION SERVICES.
CATS	CUSTOMER ACTION TEAMS.
CATV	COMMUNITY ANTENNA TELEVISION.
CAU	CONTROLLED ACCESS UNIT.
CAV	CONSTANT ANGULAR VELOCITY.
CB	CITIZEN'S BAND.
CBI	CONFEDERATION OF BRITISH INDUSTRY.
CBU	CENTRAL BANKING UNIT.
CC	COMPUTER CENTRE.
CCB	CONTROL CIRCUIT BREAKER.
CCD	COAL CONCENTRATION DEPOT.
CCE	CHIEF CIVIL ENGINEERS.
CCF	CENTRE DE CONTROLE FRET.
CCF	CONTRACT CONTROL FORM.
CCF	CONTROL CENTRE OF THE FUTURE.
CCITT	COMITE CONSULTATIF INTERNATIONAL DE TELEGRAPHIE ET TELEFONIE. (INTERNATIONAL TELEGRAPH & TELEPHONE CONSULTATIVE COMMITTEE)
CCPS	CROSS CHANNEL PASSENGER SERVICES.
CCR	CHANGE CONTROL REQUEST.
CCS	COMMUTED CHARGES SYSTEM.
CCSC	CENTRAL COACHING STOCK CONTROL.
CCTV	CLOSED CIRCUIT TELEVISION.
CD	CLOSE DOOR INDICATOR.
CDAF	CUSTOMER DIRECT ACCESS FACILTY. (TO TOPS)
CDC	COMMUNICATIONS DATA CONTROL.
CDR	CHEAP DAY RETURN (NFM).
CDROM	COMPACT DISK READ-ONLY MEMORY.
CDS	CHEAP SINGLE (NFM).
CEBCOS	CIVIL ENGINEERS BUDGET AND COSTING SYSTEM.
CEDG	CIVIL ENGINEERING DESIGN GROUP.
CEDU	CORRIDOR END DISPLAY UNIT. (ON MK3 SLEEPER VEHICLES)
CEM	COST EFFECTIVE MAINTENANCE.
CEPS	CIVIL ENGINEERS PLANT SYSTEM.
CEPT	EUROPEAN CONFERENCE OF POSTS AND TELECOMMUNICATIONS.
CES	CHIEF ESTATE SURVEYOR.
CESM	CIVIL ENGINEERS SAFETY MANUAL.
CESS	THE STRETCH OF LAND RUNNING ALONG THE OUTSIDE OF THE LINE.
CET	CENTRAL EUROPEAN TIME.
CET	CHEMICAL EMISSION TOILETS.
CETS	CIVIL ENGINEERING TECHNICAL SERVICES.
CEV	CONFERENCE EUROPEENNE DES TARIFS VOVAGEURS.
CFD	CHARGEABLE FARES DATABASE.
CFF-SBB	SWISS FEDERAL RAILWAYS.
CFL	LUXEMBOURG STATE RAILWAYS.
CFR	ROMANIAN STATE RAILWAYS. SOCIETATEA NATIONALA A CAILOR FERATE ROMANE.
CFW	CONTINANTAL FERRY WAGONS.
CGA	COLOUR GRAPHICS ADAPTER.
CH	GREEK STATE RAILWAYS.
CHEQUE	CHEQUE RECONCILIATION SYSTEM.
CHP	COAL HANDLING POINT.
CHS	CARRIAGE HOLDING SIDINGS.
CICS	CUSTOMER INFORMATION CONTROL SYSTEM.
CIE	CORAS IOMPAIR EIREANN. (IRISH RAILWAYS)
CIF	COMMON INTERFACE FILE.
CIL	CALL INFORMATION LOGGER.
CIM	CANCEL INTERPRETATION MESSAGE. (TOPS AB ENQUIRY)
CIMPS	CIVIL ENGINEERING PLANT SYSTEM.
CIS	CENTRAL INFORMATION SYSTEM.
CIS	CLEANING INFORMATION SHEETS.
CIS	CUSTOMER INFORMATION SYSTEM.
CK	COMPOSITE CORRIDOR.
CL	COMPENSATION LEAVE.
CLAIMS	INSURANCE CLAIMS SYSTEM.
CLASSMAS	CLASSIFICATION OF COST CODES MASTER FILE SYSTEM.
CLOCKWORK	COMPUTER AIDED LOCO WORKING. (LOCOMOTIVE DIAGRAMS)
CM	CENTIMETER(S).
CMD	CENTRAL MATERIALS DEPOT.
CMOS	COMPLEMENTARY METAL-OXIDE SEMICONDUCTOR.
CNR	CENTRAL NOMINATIONS AND RESULTS SYSTEM.
CO3	COMMUNICATIONS PROTOCOL SIMILAR TO 'SNA', USED ON APOLLO
CO3	AND SOME PCS FOR MAINFRAME ACCESS.
CO	CLERICAL OFFICER.
CO	CLERICAL OFFICER.
COCO	LOCO WHEEL ARRANGEMENT: 3X3 (CO-CO).
CODS	COMMERCIALISATION OF DOCUMENTATION SYSTEM.
COI	COMMUNITIES OF INTEREST.
CONPASS	CONTINENTAL PASSENGER ACCOUNTING SYSTEM.
CONT	CONTROLLED SIGNAL.
COP	CREWE OPERATIONS PRODUCTION.
COPA	CONTROL OF POLLUTION ACT (1974).
COPS	CONTAINER OPERATIONS PROCESSING SYSTEM.
COS	CONDITIONS OF SERVICE.
COS	COST OF SALE.
COS	CREWE OPERATIONS PRODUCTION.
COSHH	CONTROL OF SUBSTANCES HAZARDOUS TO HEALTH.
CP	CONTINGENCY PLANS.
CP	PORTUGUESE RAILWAYS.
CPF	CICS PRINT FACILITY.
CPF	CENTRAL PRICES FILE.
CPI	CHARACTERS PER INCH.
CPL	CHARACTERS PER LINE.
CPM	CREWE PROJECT MOVES.
CP/M	CONTROL PROGRAM FOR MICROCOMPUTERS.
CPO	CENTRAL PAYBILL OFFICE.
CPS	CENTRAL PROSECUTIONS SYSTEM.
CPU	CENTRAL PROCESSING UNIT.
CRC	CYCLICAL REDUNDANCY CHECK.
CRCC	CONTRACT REPAIR CONTROL CENTRE.
CRO	CUSTOMER RECEPTION OFFICE.
CROWS	COMPUTERISED RENEWAL OF WAY SYSTEM.
CRS	COMPUTERISED RESERVATION SYSTEM.
CRT	CATHODE RAY TUBE.
CRUCC	CENTRAL RAIL USERS' CONSULATIVE COMMITTEE.
CS	CARRIAGE SIDINGS.
CS	CENTRAL SERVICES.
CSC	CONTAINER SAFETY CONVENTION.
CSC	CREWE SUPPORT - CICS.
CSD	CARRIAGE SERVICING DEPOT.
CSD	CONCEPTUAL SYSTEMS DESCRIPTION.
CSD	CREWE SUPPORT - DATABASES.
CSD	CZECHOSLOVAKIAN STATE RAILWAYS.
CSG	CENTRAL/COMPUTER SUPPORT GROUP.
CSG	CENTRAL SERVICE GROUP.
CSM	CREWE SUPPORT - MVS.
CSMA/CD	CARRIER SENSE MULTIPLE ACCESS WITH COLLISION DETECTION.
CSO	CREWE SUPPORT ORGANISATION.
CSPG	CREWE SUPPORT - PRODUCTION.
CSPG	COMPUTER SYSTEMS PLANNING GROUP.
CSR	CAB SECURE RADIO.
CSRM	CUSTOMER SERVICE & RETAIL MANAGER.
CT	CAR TERMINAL.
CTCC	CENTRAL TRANSPORT CONSULTATIVE COMMITTEE.
CTE	CONTINUOUS TRACKTIVE EFFORT.
CTL	COMBINED TRANSPORT LIMITED.
CTO	CREWE TOPS SUPPORT.
CTOT	CLASS & TYPE OF TICKET.
CTRL	CHANNEL TUNNEL RAIL LINK.
CTT	CONSIGN THROUGH TOPS.
CUI	CUSTOMER'S UNIQUE IDENTITY (N.T.N).
CWA	CENTRAL WAGON AUTHORITY.
CWM	CARRIAGE WASHING MACHINE.
CWMD	CARRIAGE & WAGON MAINTENANCE DEPOT.
CWR	CONTINUOUS WELDED RAIL.
D&R	DIVERTED & RETIMED.
DAB	DUAL ACTING BRAKES.
DAN	DECANEWTON: A UNIT OF MEASUREMENT:
DAN	USED IN EXPRESSING TRACTIVE EFFORT.
DAT	DIGITAL AUDIO TAPE.
DB	DECIBEL(S).
DB	DUAL BRAKE.
DB	GERMAN RAILWAYS.
DG	DOWN GOODS
DBA	DATABASE ADMINISTRATOR. (MEMO)
DBA	ADJUSTED DECIBEL(S).
DBMS	DATABASE MANAGEMENT SYSTEMS.
DBSO	DRIVING BRAKE STANDARD OPEN.
DBSS	DIRECTOR BUSINESS SYSTEMS & SERVICES.
DBV	DRIVER'S BRAKE VALVE.
DBVIC	DRIVER'S BRAKE VALVE ISOLATING COCK.
DC	DATA CONCENTRATOR.
DC	DIRECT CURRENT.
DC	DISTRICT CONTROL.
DCD	DATA CARRIER DETECT.
DCD	DATA COLLECTION DEVICE.
DCE	DATA COMMUNICATIONS EQUIPMENT.
DCM	DUTY CONTRACTS MANAGER.
DD	DARLINGTON DEVELOPMENT.
DD	DIESEL DEPOT.
DDE	DIRECT DATA ENTRY.
DDI	DIRECT DIALLING IN.
DDO	DIRECT DIALLING OUT.
DECNET	DIGITAL EQUIPMENT CORPORATION'S (DEC) VERSION OF ETHERNET.
DELF	DATA ENTRY LEVEL FIVE SYSTEM.
DEMIC	A FAILURE.
DEMU	DIESEL-ELECTRIC MULTIPLE UNIT.
DEP	DESIGNATED EATHING POINT.
DET	DRIVE END TRAILER. (NO POWER)
DF	DOWN FAST.
DGL	DOWN GOODS LOOP.
DIADS	DIAGRAM INPUT ANALYSIS AND DISTRIBUTION SYSTEM.
DIC	DATA INPUT CENTRE.
DIC	DIRECTOR INTER-CITY.
DICS	DOCUMENT ISSUE CONTROL SYSTEM.
DIET	DIRECT INPUT EUROPEAN TRAFFIC
DIN	DEUTSCHE INDUSTRIE NORMENAUSSCHUSS.
DIP	DOCUMENT IMAGE PROCESSING.
DIP	DUAL IN-LINE PACKAGE.
DIST	DIRECTOR OF INFORMATION SYSTEMS & TECHNOLOGY.
DKS	DOOR KEY SWITCH.
DL	DARLINGTON LAN SUPPORT.
DLR	DOCKLANDS LIGHT RAILWAY.
DLTQ	DOWN LINE TERMINAL QUEUE. (TOPS)
DMA	DIRECT MEMORY ACCESS.
DMBC	DRIVING MOTOR BRAKE COMPOSITE.
DMBS	DRIVING MOTOR BRAKE STANDARD.
DMCL	DRIVING MOTOR COMPOSITE, LAVATORY.
DML	DOWN MAIN LINE.
DMMS	DEPOT MAINTENANCE MAINTENANCE SYSTEM.
DMMU	DIESEL MECHANICAL MULTIPLE UNIT.
DMS	DRIVING MOTOR STANDARD.
DMSL	DRIVING MOTOR STANDARD, LAVATORY.
DMU	DIESEL MULTIPLE UNIT.
DMUD	DIESEL MULTIPLE UNIT DEPOT.
DOCIMEL	CONSIGNMENT THROUGH TOPS & HERMES.
DOCS	DOCUMENTATION ORIGINATION & CONTROL SYSTEM.
DOLLY OR DUMMY	SUBSIDUARY SIGNAL.
DOM	DUTY OPERATIONS MANAGER.
DOO	DIRECTOR OF OPERATIONS.
DOPAC	DRAWING OFFICE PLANNING AND CONTROL SYSTEM.
DORIS	DESIGN OFFICE RESOURCE INFORMATION SYSTEM.
DOS	DISK OPERATION SYSTEM.
DOT	DEPARTMENT OF TRANSPORT.
DOVE	DATA OVER VOICE EQUIPMENT.
DPA	DIRECTOR OF PUBLIC AFFAIRS.
DPG	DARLINGTON PRODUCTION GROUP.
DPI	DOTS PER INCH.
DPRS	DISABLED PASSENGERS REPORTING SYSTEM.
DPSS	DIRECTOR PASSENGER SYSTEMS & SERVICES.
DPU	DIESEL PARCEL UNIT.
DR	DOUBLE ROYAL (POSTER SITE).
DRAM	DYNAMIC RANDOM-ACCESS MEMORY.
DRD	DERBY RESEARCH AND DEVELOPMENT.
DRL	DOWN RELIEF LINE.
DRS	DATA RESOURCE SYSTEM.
DRU	DATA RETRIEVAL UNIT.
DS	DOUBLE SLIP.
DS	DOWN SIDINGS.
DS	DOWN SLOW.
DSB	DANISH STATE RAILWAYS.
DSD	DRIVERS SAFETY DEVICE.
DS/DD	DOUBLE-SIDED DOUBLE-DENSITY.
DS/HD	DOUBLE-SIDED HIGH-DENSITY.
DSM	DUTY STATION MANAGER.
DT	DESK TOP.
DTCL	DRIVING TRAILER COMPOSITE, LAVATORY.
DTE	DATA TERMINAL EQUIPMENT.
DTI	DEPARTMENT OF TRADE AND INDUSTRY.
DTSOL	DRIVING TRAILER STANDARD, OPEN, LAVATORY.
DTP	DESK-TOP PUBLISHING
DUNNAGE	PACKING USED TO FILL VOID SPACES IN A LOAD.
DUPLEX	TWO INDEPENDANT DATA PATHS - SIMULTANEOUSLY BI-DIRECTIONAL
DVT	DRIVING VAN TRAILER
EAM	EAST ANGLIA. (NFM)
EBA	EMERGENCY BRAKE APPLICATION.
EBS	EMERGENCY BYPASS SWITCH.
EBT	EMMENTAL-BURGDORF-THUN RAILWAY (SWITZERLAND).
EBV	EMERGENCY BRAKE VALVE.
ECC	ERROR CORRECTION CODE.
ECE	ECONOMIC COMMISSION FOR EUROPE (OF THE UNITED NATIONS ORGANISATION IN GENEVA).
ECML	EAST COAST MAIN LINE.
ECR	ELECTRICAL CONTROL ROOM.
ECS	EMPTY COACHING STOCK.
ECU	EUROPEAN CURRENCY UNIT.
EDI	ELECTRONIC DATA INTERCHANGE.
EDIA	ELECTRONIC DATA INTERCHANGE ASSOCIATION.
EDN	EXTENDED DATA NETWORK.
EDP	EXTRA DUTY PAYMENTS.
EDRS	ELECTRONIC DEFECT REPORTING SYSTEM.
EDRS	ELECTRONIC DATA RETRIEVAL SYSTEM.
EDU	ENGINEERING DEVELOPMENT UNIT
EFAC	EUROPEAN FREIGHT ACCOUNTANCY CENTRE
EFL	EXTERNAL FINANCE LIMIT.
EFTPOS	ELECTRONIC FUNDS TRANSFER AT POINT OF SALE
EG	EXECUTIVE GRADE.
EGA	ENHANCED GRAPHICS ADAPTER.
EHA	ELECTRICALLY HEATED, AIR CONDITIONED STOCK
EIA	ELECTRONIC INDUSTRIES ASSOCIATION.
EIS	EQUIPMENT INVENTORY SYSTEM.
EISA	EXTENDED INDUSTRY-STANDARD ARCHITECTURE.
ELIPS	ELECTRONIC PARTS SYSTEM.
ELR	EARTH LOOP RECALL. (USED ON PBX'S)
ELR	ENGINEERS LINE REFERENCE.
EMAIL	ELECTRONIC MAIL.
EMI	ELECTROMAGNETIC INTERFERENCE.
EMM	EXPANDED MEMORY MANAGER.
EMS	EXPANDED MEMORY SPECIFICATION.
EMU	ELECTRIC MULTIPLE UNIT.
EMUD	ELECTRIC MULTIPLE UNIT DEPOT.
ENFE	EMPRESA NACIONAL FERROCARRILES (BOLIVIAN RAILWAYS).
EO	ENGINE ONLY.
EOS	ENGINE OVERSPEED DEVICE.
EPA	ENVIRONMENT PROTECTION ACT (199O).
EPB	ELECTRO-PNEUMATIC BRAKE.
EPP	ENHANCED PARALLEL PORT.
EPROM	ERASABLE PROGRAMMABLE READ-ONLY MEMORY.
EPS	EUROPEAN PASSENGER SERVICES.
EPU	ELECTRIC PARCELS UNIT.
ER	EMPLOYEE RELATIONS.
ER	EASTERN REGION (FORMER).
ERIC	ENHANCED RAILFREIGHT INTERMODEL CONTROL SYSTEM.
EROS	EMERGENCY RESTRICTION OF SPEED.
ERS	EMERGENCY REPLACEMENT SIGNAL.
ERTAC	EUROPEAN RAIL TRAFFIC ACCOUNTING SYSTEM.
ESD	ELECTROSTATIC DISCHARGE.
ESDI	ENHANCED SMALL-DEVICE INTERFACE.
ESIPS	ELECTRICITY SUPPLY INDUSTRY PRIVATISATION PROPOSALS.
ESM	ESTATE SURVEYOR AND MANAGER.
ESR	EMERGENCY SPEED RESTRICTION.
ETA	ESTIMATED TIME OF ARRIVAL.
ETB	ELECTRIC TOKEN BLOCK.
ETD	ESTIMATED TIME OF DEPARTURE.
ETD	EXTENSION TRUNK DIALING.
ETH	ELECTRIC TRAIN HEATING.
ETHERNET	ONE OF THE OLDEST LAN TECHNOLOGIES, ORIGINALLY DEVELOPED BY XEROX, TO RUN OVER COAXIAL CABLE.
ETR	ELECTRIFIED THIRD RAIL.
ETR	EXECUTIVE RETURN (NFM).
ETRB	ELECTRONIC TRAIN REGISTER BOOK.
ETS	ELECTRIC TRAIN SUPPLY.
ETS	EXECUTIVE SINGLE (NFM).
EVC	EUROPEAN VINYLS CORPORATION.
EXS	EXCHANGE SIDING.
F	FARENHEIT.
F&S	FULL & STANDING.
FABS	FREIGHT ACCOUNTING BUSINESS SYSTEM.
FACETS	FULLY AUTOMATED COMPUTER ENQUIRY & TICKETING SYSTEM.
FALCON	FAULT CONTROL MANAGEMENT SYSTEM.
FAMOUS	FORECASTING AND MONITORING OF USER STATISTICS.
FART	FAST ACTION RESPONSE TEAM (NSE)
FASCIA	FIXED ASSET SYSTEM, CONTROL INFORMATION AND ACCOUNTING.
FASTA	FINANCIAL ACCOUNTING SYSTEM TRAVEL AGENTS.
FAT	FILE ALLOCATION TABLE.
FAX	FACSIMILE.
FAXGATE	INTERFACE FROM MAINFRAME COMPUTERS TO FACSIMILE.
FB	FLAT BOTTOMED RAIL.
FC	FLAT CROSSING.
FCC	FEDERAL COMMUNICATIONS COMMISSION.
FD	FREIGHT DEPOT.
FDC	FIELD DIVERT CONTROL.
FDDI	FIBRE DISTRIBUTED DATA INTERFACE.
FDM	FREQUENCY-DIVISION MULTIPLEX.
FDR	FIRST CLASS DAY RETURN (NFM).
FDS	FIRST CLASS DAY SINGLE (NFM).
FEP	FRONT END PROCESSOR.
FEPASA	FERROVIAS PAULISTA S.A. (BRAZILIAN RAILWAY OPERATING CO.)
FERITT	FILE ENQUIRY REQUESTS INPUT THROUGH TERMINALS.
FET	FIELD EFFECT TRANSISTOR.
FILE SERVER	THE HEART OF A LAN, HOLDING FILES THAT EVERYONE CAN USE.
FIP	INTERNATIONAL GROUP FOR THE EXCHANGE OF TRAVEL FACILITIES.
FIRE	ENGINE FIRE WARNING SYSTEM.
FK	FIRST CORRIDOR.
FLB	FULL LIFTING BARRIERS
FLE	FREIGHTLINER EUROPE.
FLT	FREIGHTLINER TERMINAL.
FM	FREQUENCY MODULATION.
FO	FIRST OPEN.
FOOTEX	FOOTBALL EXCURSION.
FOR	FIRST CLASS OPEN RETURN (NFM).
FOU	FREIGHT OPERATING UNIT.
FOUR FOOT	THE GAP BETWEEN THE RUNNING RAILS. (4' 8 1/2")
FP	FUELLING POINT.
FPM	FIRE PRECAUTIONS MANAGER.
FPP	FUEL PRIMING PUMP.
FR	FINAL REMUNERATION.
FRAME	FAULT REPORTING AND MONITORING OF EQUIPMENT.
FREDA	FREIGHT REVENUE EXPENDITURE DEBITING AND ACCOUNTING SYATEM.
FREIGHTLAND	LAND DATABASE SYSTEM.
FREQUENCY	THE RATE AT WHICH A SIGNAL ALTERNATES, USUALLY EXPRESSED IN CYCLES OR HERTZ (HZ).
FRPS	FEDERATION OF PROFESIONAL RAILWAY STAFF.
FS	ITALIAN STATE RAILWAYS.
FSG	FINANCE SYSTEMS GROUP.
FSK	FREQUENCY SHIFT KEYING.
FTA	FREIGHT TRANSPORT ASSOCIATION.
FTF	FILE TO FILE.
FTS	FIRST CLASS SINGLE TICKET (NFM).
FUMES	FUEL & MILEAGE SYSTEM.
G	GRAM(S).
G	GRAVITIES.
G	GREEN SIGNAL.
G&SW (GSW)	GLASGOW AND SOUTH WESTERN.
GA	GROUP ADDRESS.
GATEWAY	A COMBINATION OF HARDWARE AND SOFTWARE THAT INTERCONNECTS OTHERWISE INCOMPATIBLE NETWORKS OR NETWORKING DEVICES.
GB	GIGABYTE(S).
GBTT	GREAT BRITAIN TIMETABLE.
GCAS	GUARDS COUNT ANALYSIS SYSTEM.
GDS	GLOBAL DISTRIBUTION SYSTEM.
GE	GREAT EASTERN
GEMINI	MAINFRAME SYSTEM FOR CONTROL & MAINTENANCE OF THE DMU FLEET. (PROMISE 3)
GEOGIS	GEOGRAPHY AND INFRASTRUCTURE COMPUTER SYSTEM.
GF	GROUND FRAME.
GIGA	A PREFIX DENOTING ONE BILLION.
GIJ	GLUED INSULATED JOINT. (RAIL)
GLW	GROSS LADEN WEIGHT. (MAXIMUM WEIGHT OF A LOADED WAGON)
GMP	GUARANTEED MINIMUM PENSION.
GMT	GREENWICH MEAN TIME.
GPO	GENERAL POST OFFICE (ROYAL MAIL).
GPR	GENERAL PURPOSE RELIEF.
GTN	GOVERNMENT TELECOMS NETWORK.
GUI	GRAPHICS USER INTERFACE.
GUV	GENERAL UTILITY VAN. (OPEN)
GWML	GREAT WESTERN MAIN-LINE.
GWR	GREAT WESTERN RAILWAY.
H	HEXADECIMAL.
H&S	HEALTH AND SAFETY.
HABD	HOT AXLE BOX DETECTOR.
HALF-DUPLEX	SINGLE DATA PATH, BI-DIRECTIONAL BUT ONE WAY AT A TIME.
HASAW	HEALTH AND SAFETY AT WORK.
HC	HARD COPY.
HDLC	HIGH LEVEL DATA LINK CONTROL.
HERMES	EUROPEAN RAILWAYS DATA EXCHANGE LINKS.
HERTZ (HZ)	A UNIT FOR MEASURING FREQUENCY, ONE HERTZ (HZ) EQUALS ONE CYCLE PER SECOND.
HGD	HIGHER GRADE DUTY.
HL	HEADQUARTERS GROUP - LAN SUPPORT.
HLWD	HIGH LEVEL WORKING DOCUMENT. (BRPTT)
HMA	HIGH MEMORY AREA.
HOS	HEAD OF SECTION.
HPD	HEADQUARTERS DEVELOPMENT.
HPFS	HIGH-PERFORMANCE FILE SYSTEM.
HQ	HEADQUARTERS.
HR	HUMAN RESOURCES.
HS	HOLDING SIDINGS.
HSC	HEALTH AND SAFETY COMMISSION.
HSDR	HIGH SPEED DATA RING.
HSE	HEALTH AND SAFETY EXECUTIVE.
HSR	HIGH SAVER RETURN (NFM).
HST	HIGH SPEED TRAIN.
HSTD	HST DEPOT.
HSTRC	HIGH SPEED TRACK RECORDING COACH.
HUB	THE CENTRE OF A STAR TOPOLOGY NETWORK OR CABLING SYSTEM: FILE SERVERS ARE OFTEN THE HUB OF THE LAN.
HZ	HRVATSKE ZELJEZNICE : CROATION RAILWAYS.
IAM	INNOVATION ACCESS METHOD.
IBHI	INTERMEDIATE BLOCK HOME SIGNAL.
IBIS	INTERNAL BUSINESS INVOICING SYSTEM.
IBJ	INSULATED BLOCK JOINT.
IBM	INTERNATIONAL BUSINESS MACHINES.
IBMCS	INTERNATIONAL BUSINESS MACHINES CABLING SYSTEM.
IBS	INTERMEDIATE BLOCK SIGNAL.
ICCR	INTER-COMPUTER CONNECTING RING.
IC	INTERCITY.
ICL	INTERNATIONAL COMPUTERS LIMITED.
ICOBS	INTERCITY ON-BOARD SERVICES.
ID	IDENTIFICATION.
IDB	INFRASTRUCTURE DATABASE.
IDE	INTEGRATED DRIVE ELECTRONICS.
IECC	INTEGRATED ELECTRONIC CONTROL CENTRE.
IEEE	INSTITUTE OF ELECTRICAL AND ELECTRONIC ENGINEERS.
IETD	INTERNATIONAL EXTENSION TRUNK DIALLING.
IFC	INFRASTRUTURE FAULT CONTROLLER.
IFM	IRISH FARES MANUAL.
IFTM	INTERNATIONAL FREIGHT TRAFFIC MANUAL.
ILC	IS LINE CLEAR.
ILWS	INDUCTIVE LOOP WARNING SYSTEM.
IMACS	INVENTORY MANAGEMENT AND ACCOUNTING CONTROL SYSTEM.
IMDG	INTERNATIONAL MARITIME DANGEROUS GOODS (CODE).
IMPACT	INVESTMENT MANAGEMENT PROJECT ACCOUNTING CONTROL TOOLS.
IMPS	INVESTMENT MONITORING & PLANNING SYSTEM.
INFORMS	INTEGRATED NATIONAL FREIGHT OPERATING RESOURCES MANAGEMENT SYSTEM.
INIS	INTEGRATED NATIONAL INTELLIGENCE SYSTEM.
INS	INTERNATIONAL NETWORK SERVICES.
INTERFRIGO	OPERATOR OF PRIVATLEY OWNED WAGONS.
INVIEW	INVESTMENT REVIEW SYSTEM. (REPLACED BY IMPS)
I/O	INPUT/OUTPUT.
IOM	INPUT/OUTPUT MODULE.
IPAC	INTERNATIONAL PASSENGER ACCOUNTING CENTRE. (BRIGHTON)
IPC	INTERPROCESS COMMUNICATIONS.
IPL	INITIAL PROGRAM LOAD.
IPTIS	INTERNATIONAL PRIVILEGE TICKET ISSUE SECTION.
IR	IRISH RAIL.
IR	INLAND REVENUE.
IRCA	INTERNATIONAL RAIL CONGRESS ASSOCIATION.
IRIS	INCIDENT ROOM INFORMATION SYSTEM.
IRJ	INSULATED RAIL JOINT.
IRQ	INTERRUPT REQUEST.
IRS	INTERNATIONAL RESERVATION SYSTEM.
IRT	INTEGRATED RETAIL UNIT.
IRTU	INTERNATIONAL ROAD TRANSPORT UNION.
ISA	INDUSTRY STANDARD ARCHITECTURE.
ISDN	INTEGRATED SERVICES DIGITAL NETWORK.
ISO	INDEPENDENT STATION OPERATOR.
ISO	INTERNATIONAL STANDARDS ORGANISATION.
ISRS	INTERNATIONAL SAFETY RATING SYSTEM.
ISU	INFRASTRUCTURE SERVICE UNIT.
IT	INCLUSIVE TOUR.
IT	INFORMATION TECHNOLOGY.
ITS	INTERNATIONAL TICKETING SYSTEM.
ITT	INVITATION TO TENDER.
IUP	IRREGULAR & UNSOCIAL HOURS PAYMENT.
IVL	INTERACTIVE VIDEO LEARNING.
JACW	JOINT ADVISORY COUNCIL FOR WELFARE.
JAO	JOINT ACCOUNTING OFFICE.
JB	JOINT BUSINESS.
JBMT	JOINT BUSINESS MANAGEMENT TEAM.
JDS	JOINT DISTRIBUTION SYSTEM.
JEIDA	JAPANESE ELECTRONIC INDUSTRY DEVELOPMENT ASSOCIATION.
JES	JOB ENTRY SUB-SYSTEM.
JETS	JOURNEY ENTRY TRANSFER SYSTEM. (REPLACED BY AXIS)
JIS	JOINT INDUSTRY PENSION SCHEME.
JN OR JCN	JUNCTION.
JOC	JOINT OPERATING COMMITTEE. (OF PWF)
JOCKO	SHUNTING LOCOMOTIVE.
JZ	YUGOSLAVIAN RAILWAYS.
KBIT	1024 BITS, THE EQUIVALENT OF 128 BYTES.
KBIT	1024 BITS, THE EQUIVALENT OF 128 BYTES.
KB	1024 BYTES
KB/SEC	KILOBYTE(S) PER SECOND.
KBIT(S)/SEC	KILOBIT(S) PER SECOND.
KCRC	KOWLOON - CANTON RAILWAY CORPORATION
KHZ	KILOHERTZ.
KILOBIT	1024 BITS, THE EQUIVALENT OF 128 BYTES.
KILOBYTE	1024 BYTES
KSR	KEYBOARD, SEND, RECEIVE. (N.T.N)
LAN	LOCAL AREA NETWORK.
LAREBUD	LABOUR RESOURCES BUDGET SYSTEM.
LASER	LIGHT AMPLIFICATION BY THE STIMULATED EMISSION OF RADIATION.
LASERS	LOCAL AREA SCHEME RECORD SYSTEM.
LATA	LINE AND TERMINAL ADDRESS. (TOPS)
LATIN	LOCAL ACCESS TO TRAIN INFORMATION.
LC	LEVEL CROSSING.
LCB	LIGHTING CIRCUIT BREAKER.
LCD	LIQUID CRYSTAL DISPLAY.
LD	LIGHT DIESEL LOCOMOTIVE.
LDB	LOCAL DATABASE.
LDC	LOCAL DEPARTMENTAL COMMITTEE: 'A' SALARIED, 'B' FOOTPLATE, 'C' CONCILIATION, 'D' PW,OLE & S+T., 'E' SHIPPING.
LDG	LIST OF DANGEROUS GOODS.
LDR	LOW DAY RETURN (NFM).
LDS	LOCAL DOOR SWITCH. (SLIDING DOOR TRAIN)
LED	LIGHT EMITTING DIODE.
LEV	LIGHT ECONOMY VEHICLE.
LFM	LOCAL FARES MANUAL.
LHCS	LOCOMOTIVE HAULED COACHING STOCK.
LH	LEFT HAND.
LHS	LEFT HAND SIDE.
LHS	LOCOMOTIVE HOLDING SIDING.
LIF	LOW INSERTION FORCE.
LIFT	LONDON INTERNATIONAL FREIGHT TERMINAL.
LIM	LINEAR INDUCTION MOTOR.
LIM	LOTUS/INTEL/MICROSOFT.
LMR	LONDON MIDLAND REGION (FORMER).
LIP	LOCOMOTIVE INSPECTION POINT.
LNCI	LONDON NETWORK CONTROL INTERFACE.
LNIATA	LINE NUMBER INTERFACE ADDRESS TERMINAL ADDRESS. (CRS)(6CHAR)
LLC	LOGICAL LINK CONTROL.
LOB	LENGTH OF BUFFERS.
LOOU	LOCKED OUT OF USE.
LOP	LOSS OF POWER.
LOR	LINE OF ROUTE.
LOS	LIMIT OF SHUNT.
LOVERS	LOCAL VEHICLE RECORDS SYSTEM.
LPG	LIQUIFIED PETROLEUM GAS.
LPI	LINES PER INCH.
LPRBCICS	THIS IS WHERE THE FOLLOWING APPLICATIONS RESIDE: RAVERS.
LQP	LETTER QUALITY PRINTER.
LRPC	LONDON REGIONAL PASSENGER COMMITTEE.
LRQA	LLOYD'S REGISTER QUALITY ASSURANCE.
LRT	LONDON REGIONAL TRANSPORT.
LRT	LIGHT RAPID TRANSPORT.
LSB	LOCAL START BUTTON.
LSD	LOCAL SERVICE DIAGRAMS.
LSE	LUZERN STANS ENGELBERG RAILWAY. (SWITZERLAND)
LSP	LINE SIDE PILLAR.
LSR	LOW SAVER RETURN (NFM).
LT	LONDON TRANSPORT.
LTS	LONDON TILBURY & SOUTHEND.
LU	LOGICAL UNIT.
LU 6.2	A 2 WAY AUTOMATICALLY INITIATED COMMUNICATION BETWEEN
LU 6.2	MAINFRAME AND TERMINAL.
LUL	LONDON UNDERGROUND LIMITED.
LVRS	LOCAL VEHICLE RECORDS SYSTEM.
M	METER(S).
MA	MILLIAMPERE(S).
MAH	MILLIAMPERE HOUR(S).
M&EE	MECHANICAL & ELECTRICAL ENGINEERING.
MAC	MULTIPLE ACCESS COMPUTER.
MAG-LEV	MAGNETIC LEVITATION: A VEHICLE WITH A LIM PROPULSION SYSTEM.
MAIDEN	LOCAL SYSTEM OF TRAIN CREW DIAGRAM PRODUCTION.
MAN	METROPOLITAN AREA NETWORK.
MANIS	MANPOWER INFORMATION SYSTEM.
MAP	MANUAL OF AGREED PATHWAYS.
MAP	MANUFACTURING AUTOMATION PROTOCAL.
MARPAS	MAINTENANCE & RENEWAL PLANNING AID SYSTEM.
MARS	MAINTENANCE & REPAIR SCHEDULER SYSTEM.
MAS	MULTIPLE ASPECT SIGNALLING.
MAV	HUNGARIAN STATE RAILWAYS.
MB	MEGABYTE(S).
MBO	MANAGEMENT BUY-OUT.
MCB	MAIN CIRCUIT BREAKER.
MCI	MANAGEMENT COURSE INSTRUCTION.
MCI	MANAGEMENT CHARTER INITIATIVE.
MCT	MULTI-CONVERSION TRANSACTION.
MCT	MARITIME CONTAINER DEPOT.
MD	MANAGING DIRECTOR.
MDA	MONOCHROME DISPLAY ADAPTER.
MEAV	MODERN EQUIVALENT ASSET VALUE
MEBO	MANAGEMENT AND EMPLOYEE BUY-OUT.
MEBS	MECHANICAL ENGINEERS BUDGETING SYSTEM.
MEGA	A PREFIX TO DENOTE A MILLION, IE A MEGABYTE OR MEGABIT.
MEL	MINIMUM EARNINGS LEVEL.
MEM	FORMER MIDLAND AND SCOTTISH REGIONS (NFM).
MEMFIS	MICROCOMPUTER EQUIPMENT MAINTENANCE FILE INFORMATION SYSTEM.
MEMO	MANAGERS ELECTRONIC MAILING OPTION.
MEND	MENU DRIVEN ENQUIRY SYSTEM.
MGA	MONOCHROME GRAPHICS ADAPTER.
MGL	MULTI-GROOVE LOCKING PINS. (HUCK BOLT)
MGR	MERRY-GO-ROUND.
MGRPLAN	LOCAL SYSTEM FOR PLANNING MGR SERVICES.
MHCA	MODIFIED HISTORIC COST ACCOUNTING.
MHZ	MEGAHERTZ.
MIB	MANAGEMENT INFORMATION BASE.
MIC	MUTUAL IMPROVEMENT CLASS.
MICROPROCESSER	A CPU ON ONE CHIP.
MID	MATERIAL ISSUE DOCUMENT.
MIDI	MUSICAL INSTRUMENT DIGITAL INTERFACE.
MIF	MATERIAL INCIDENT FORM.
MIFT	MANCHESTER INTERNATIONAL FREIGHT TERMINAL.
MILES	DMU MILAGE. (ER)
MIPS	MANAGEMENT INFORMATION PACKAGE SYSTEM. (FOR NTN BILLING)
MIPS	MILLIONS OF INSTRUCTIONS PER SECOND.
MIS	MANAGEMENT INFORMATION SYSTEM.
MITS	MATERIALS AND INFRASTRUCTURE TESTING SERVICES.
MLB	MAIN LINE BALANCING.
MLV	MOTOR LUGGAGE VAN.
MML	MIDLAND MAIN-LINE.
MNC	MINIMUM NEGOTIATED CURVE.
MNS	MANAGED NETWORK SERVICE. (IBM)
MOB	MONTREUX-OBERLAND-BERNOIS RAILWAY (SWITZERLAND).
MOD	MINISTRY OF DEFENCE.
MODA	MINISTRY OF DEFENCE, ARMY.
MOS	MOBILE OPERATING SUPERVISOR (NSE)
MODEM	MODULATOR - DEMODULATOR.
MOSS	MODELLING SYSTEM.
MP	MILE POST.
MPA	MINIMUM PENSION AGE.
MPJ	MESSAGE PROCESS JOB.
MPH	MILES PER HOUR.
MRN	MATERIAL RECEIPT NOTE.
MRP	MAIN RESERVOIR PIPE.
MRPS	MAINTENANCE RESOURCES PLANNING SYSTEM.
MRS	MATERIALS REQUIREMENT SCHEDULE.
MS	MANAGEMENT STAFF.
MS	MILLISECOND(S).
MS-DOS	MICROSOFT DISK OPERATING SYSTEM.
MSNF	MULTIPLE SYSTEM NETWORKING FEATURE.
MSNJC	MANAGEMENT STAFF NATIONAL JOINT COMMITTEE.
MSO	MOTOR STANDARD OPEN.
MSOL	MOTOR STANDARD OPEN, LAVATORY.
MSS	MAXIMUM SERVICE SPEED.
MT	MOTORAIL TERMINAL.
MTBF	MEAN TIME BETWEEN FAILURE.
MTE	MAXIMUM TRACTIVE EFFORT. .
MTFC	MIDLAND TERMINAL FAULT CONTROL.
MTHB	MITTEL-THURGAU RAILWAY (SWITZERLAND).
MTS	MASTER TIMETABLE SYSTEM (SR).
MULES	MULTIPLE UNIT LOCATION & ENQUIRY SYSTEM.
MV	MILLIVOLT(S).
MVS	MULTIPLE VIRTUAL STORAGE
MVS/XA	MULTIPLE VIRTUAL STORAGE/EXTENDED ARCHITECTURE
MXC	MIDLAND CROSS COUNTRY.
N	NORMAL (POSITION OF POINTS).
NA	NOT ADVERTISED.
NA	NOT AVAILABLE / NOT APPLICABLE.
NAB	NETWORK AWAYBREAK RETURN (NFM).
NALCO	NATIONAL LOCATION CODES MASTER FILE SYSTEM.
NAMAS	NATIONAL MEASUREMENT ACCREDITATION SERVICE.
NAPS	NATIONAL ACCOUNTS PAYBILL SYSTEM (DERBY)
NAPUSS	NATIONAL ACCOUNTS PAYABLE UTILITIES SUB-SYSTEM.
NC	NOTTINGHAM COMMUNICATIONS SUPPORT.
NCAC	NATIONAL CONTINENTAL ACCOUNTING CENTRE.
NCAS	NATIONAL COAL ACCOUNTING SYSTEM (REPLACED BY FABS).
NCB	NATIONAL COAL BOARD.
NCB	NOTTINGHAM COMMUNICATIONS BATCH.
NCI	NETWORK CONTROL INTERFACE.
NCP	NOTTINGHAM CAPACITY PLANNING.
NCS	NOTTINGHAM CUSTOMER SUPPORT.
NCVQ	NATIONAL COUNCIL FOR VOCATIONAL QUALIFICATIONS.
ND	NOTTINGHAM DEVELOPMENT.
NDF	NO DEFECT FOUND.
NDIS	NETWORK DRIVER INTERFACE SPECIFICATION.
NEBSM	NATIONAL EXAMINATION BOARD OF SUPERVISORY MANAGEMENT.
NDT	NON DESTRUCTIVE TESTING.
NEP	NON ENHANCED PAYMENT.
NEQ	NET EXPLOSIVE QUANTITY.
NET	NORMES EUROPEENNE DE TELECOMMUNICATIONS.
NETWARE	LAN NETWORKING PRODUCTS INCLUDING AN OPERATING SYSTEM DEVELOPED BY NOVELL INC.
NFAAS	NATIONAL FREIGHT ACCOUNTING ANG ANALYSIS SYSTEM.
NFM	NATIONAL FARES MANUAL.
NG	NORMAL GRADE. (RAIL STEEL)
NGT	NEW GENERATION TICKETING SYSTEM
NICAD	NICKEL CADMIUM.
NI	NATIONAL INSURANCE.
NIEAAS	NATIONAL INTEGRATED ENGINEERING ACCOUNTS AND ANALYSIS SYSTEM
NIMH	NICKEL-METAL HYDRIDE.
NIR	NORTHERN IRELAND RAILWAYS.
NIV	NOTTINGHAM INTERNATIONAL VIEWDATA.
NJC	NATIONAL JOB CODE.
NLC	NATIONAL LOCATION CODES MASTER FILE SYSTEM.
NMC	NETWORK MANAGEMENT CENTRE.
NMI	NONMASKABLE INTERRUPT.
NODES	DEVICES ON A NETWORK THAT DEMAND OR SUPPLY SERVICES OR WHERE TRANSMISSION PATHS ARE CONNECTED.
NPAAS	NATIONAL PASSENGER ACCOUNT ALLOCATION SYSTEM.
NPCCS	NON-PASSENGER CARRYING COACHING STOCK.
NPS	NATIONAL PAYROLL SYSTEM.
NPSIA	NATIONAL PAYROLL SYSTEM: PHASE 1A.
NRA	NATIONAL RIVERS AUTHORITY.
NRCC	NETWORK REPAIR CONTRACT CONTROL.
NRN	NATIONAL RADIO NETWORK.
NRP	NATIONAL RADIO PLAN.
NRT/NRTO	NATIONAL ROAD TRANSPORT ORGANISATION.
NS	NANOSECOND(S).
NS	DUTCH STATE RAILWAYS.
NSB	NORWEGIAN STATE RAILWAYS.
NSC	NATIONAL SUPPLY CENTRE.
NSE	NETWORK SOUTHEAST.
NST	NO SIGNALMAN TOKEN.
NTCR	NON-TRAIN CREW ROSTERS (SCR).
NTN	NATIONAL TELEPRINTER NETWORK.
NTP	NATIONAL TELECOMMS PLAN.
NUR	NATIONAL UNION OF RAILWAYMEN (NOW RMT).
NVQ	NATIONAL VOCATIONAL QUALIFICATIONS.
NVRAM	NONVOLATILE RANDOM ACCESS MEMORY.
NWR	NORMAL WORKING RESUMED.
NX	ENTRANCE EXIT (PANEL SIGNALLING).
NY	NETWORK YARD.
OB	ON BLOCK.
OBB	AUSTRIAN NATIONAL RAILWAYS.
OBS	ON BOARD SERVICES.
OCB	OPEN CIRCUIT BREAKER (OLE).
OCC	ON-LINE CHANGE CONTROL.
OCC	OPERATIONS CONTROL CENTRE.
OCS	ON COMPANY SERVICE.
OCS	ONE CONTROL SWITCH.
ODM	OUTSIDE DEPOT MAINTENANCE.
ODS	OPERATIONS DEPARTMENT SUPERVISOR.
OE	OUTSIDE EDGE. (NON-GAUGE FACE OF RAIL)
OEL	OCCUPATIONAL EXPOSURE LIMIT.
OEM	OWN EQUIPMENT MANUFACTURER.
OFF	SIGNAL EXHIBITING A PROCEED ASPECT.
OFQ	ORGANISING FOR QUALITY.
OHLE	OVERHEAD LINE EQUIPMENT.
OHS	OCCUPATIONAL HEALTH SERVICE.
OIH	OCCUPATIONAL ILL HEALTH.
OIS	OPERATIONAL INFORMATION SYSTEMS.
OJEC	OFFICIAL JOURNAL FOR THE EUROPEAN COMMUNITIES.
OLGA	ON-LINE GAUGING APPARATUS.
OLE	OBJECT LINKING AND EMBEDDING.
OLE	OVERHEAD LINE EQUIPMENT.
OLR	OVERLOAD RELAY
OMEGA	OPERATIONS, MEE & GENERAL DEPARTMENTS ACCOUNTING SYSTEM.
OMO	ONE MAN OPERATION (DOO).
ON	SIGNAL EXHIBITING A STOP ASPECT.
ONCFM	MOROCCAN STATE RAILWAYS.
OOG	OUT OF GAUGE.
OOO	OUT OF ORDER.
OPECC	ONLINE PROJECT EVALUATION AND CENTRE CONTROL.
OPQ	OCCUPATIONAL PERSONALITY QUESTIONARE.
ORCATS	OPERATIONAL RESEARCH COMPUTER ALLOCATION OF TICKETS TO SERVICE
ORE	OFFICE FOR RESEARCH & EXPERIMENTS. (OF THE UIC)
ORF	OIL REFINERY.
OS	OUT-STANDING.
OS	OUT-STATION.
OSCA	OPEN SYSTEMS CABLING ARCHITECTURE.
OSG	OPERATIONS SUPPORT/STRATEGY GROUP.
OSI	OPEN SYSTEMS INTERCONNECTION.
OT	OVERTIME.
OTMRS	ON TRAIN MONITORING AND RECORDING SYSTEM.
OTP	ONE-TIME PROGRAMMABLE.
OTW	ONE TRAIN WORKING.
P&O	PENINSULAR AND ORIENTAL (STEAMSHIP COMPANY).
PA	PUBLIC ADDRESS.
PABX	PRIVATE AUTOMATIC BRANCH EXCHANGE
PAC	PERSONAL ACCESS CODE.
PACC	PASSENGER ACCOUNTING CONTROL CENTRE (YORK).
PAD	PACKET ASSEMBLER/DISASSEMBLER.
PADS	PARTS AND DRAWING SYSTEM.
PAL	PHASE ALTERNATE LINE.
PAL	PROGRAMMABLE ARRAY LOGIC.
PALADIN	PERFORMANCE AND LOADING ANALYSIS DATABASE OF INFORMATION.
PAMAPS	PLANNING AND MANAGEMENT ACCOUNTING SYSTEM.
PAMS	PORTIS/APTIS MONITORING SYSTEM.
PARIS	PARCELS ACCOUNTING AND REVENUE INFORMATION SYSTEM.
PASSCOM	PASSENGER COMMUNICATION EQUIPMENT.
PASSTP	PASSENGER TRAIN PUNCTUALITY (LMR).
PATHWAY	LOCAL SYSTEM FOR PRODUCING PATHING REQUIREMENTS.
PB	PULLMAN BRAKE FIRST.
PBL	POUSSOIR BOUTON LOCOMOTIVE (CLASS 58 BRAKES).
PBM	PARCELS BUSINESS MACHINE.
PBX	PRIVATE BRANCH EXCHANGE.
PC	PERSONAL COMPUTER (IBM EQUIVALENT).
PC	PULLMAN PARLOUR FIRST.
PCC	POWER CONTROL CIRCUIT.
PCC	PROTOCOL CONCENTRATOR CONVERTOR
PCD	PARCELS CONCENTRATION DEPOT.
PCM	PULSE CODE MODULATION.
PCMCIA	PERSONAL COMPUTER MEMORY CARD INTERNATIONAL ASSOCIATION.
PCN	PERSONAL COMMUNICATIONS NETWORK.
PCR	POWER CONTROL RELAY.
PD	PARCELS DEPOT.
PDN	PUBLIC DATA NETWORK.
PDS	PREMISIS DISTRIBUTION SYSTEM.
PDT	PORTABLE DATA TERMINAL.
PEARLS	PERSONNEL ADMINISTRATION RECORDS: LOCAL SYSTEM.
PEARS	PALADIN EXTRACT AND REPORTING SYSTEM.
PEF	POWER EARTH FAULT.
PENSON	PENSION FUND SYSTEM
PERCIS	PERSONNEL CORPORATE INFORMATION SYSTEM.
PERS	POLICE EMPLOYEE RECORDS SYSTEM.
PERVACS	PERSONNEL VACANCY SYSTEM.
PFRI	PRINT FACILITY REPORT INDEX.
PGA	PIN-GRID ARRAY.
PHC	PERIODIC HEAVY CLEAN.
PHIRES	PLANT HIRE SYSTEM (REPLACED BY CEPS).
PHIS	PERFORMANCE HISTORICAL INFORMATION SYSTEM.
PICOP	PERSON IN CHARGE OF POSSESSION.
PICOW	PERSON IN CHARGE OF WORK.
PICS	PEARLS INSTRUCTION CONTROL SYSTEM.
PIDS	PASSENGER INFORMATION DISPLAY SYSTEMS (ER).
PILOT	SHUNTING LOCOMOTIVE.
PIM	PASSENGER INSTRUCTION MANUAL.
PIM	PERSONAL INFORMATION MANAGER.
PIMS	PROCUREMENT INFORMATION MANAGEMENT SYSTEM.
PIONEERS	PAYROLL INFORMATION ONLINE ENQUIRY AND REPORTING SYSTEM.
PIM	PASSENGER INSTRUCTIONS MANUAL.
PINS	POLICE INFORMATION SYSTEM.
PIRATES	PASSENGER INFORMATION, RESERVATION/REVENUE ACCOUNTING AND TICKETING FOR EUROPE SYSTEM.
PITG	PERSONNEL INFORMATION TECHNOLOGY GROUP.
PJD	PLANNED JOB DATABASE.
PK	PULLMAN FIRST KITCHEN.
PKP	POLISH STATE RAILWAYS.
PL	PAID LEAVE.
PLOD	POLICE LOGISTICAL & OPERATIONAL DATABASE.
PLS	POSITION LIGHT SIGNAL (SUBSIDIARY SIGNAL).
PMLAA	PROVIDENT MUTUAL LIFE ASSURANCE ASSOCIATION.
PMR	PRODUCTION MODIFICATION REQUEST
PMS	PANTOGRAPH MOTOR SECOND.
PNB	PHYSICAL NEEDS BREAK.
PNR	PASSENGER NAME RECORD.
PO	PRIVATE OWNER.
PO	POST OFFICE.
POIS	PASSENGER TOPS (PASSENGER OPERATIONS INFORMATION SYSTEM).
POL	PRIMARY OVERLOAD.
PON	PERIODICAL OPERATING NOTICE.
PORT	ENTRANCE OR ACCESS POINT TO A COMPUTER OR OTHER DEVICE.
PORTIS	PORTABLE TICKET ISSUING SYSTEM.
POS	POST OFFICE SORTING VEHICLE.
POSERS	PROJECT OFFICE SCHEMES RECORD SYSTEM.
POST	POWER-ON SELF-TEST.
POSTERS	PROJECT OFFICE SCHEME TARGET ENQUIRY RECORD SYSTEM.
POT	POST OFFICE STOWAGE VEHICLE.
POTIS	PASSENGER OPERATED TICKET ISSUING SYSTEM.
PPSG	PERSONNEL AND PAYROLL SYSTEMS GROUP.
PP&CCA	PROFIT PLANNING AND COST CENTRE ANALYSIS (REPLACED BY SPAMS).
PPE	PERSONAL PROTECTION EQUIPMENT.
PPM	PAGES PER MINUTE.
PPM	PLANNED PREVENTATIVE MAINTENANCE.
PQFP	PLASTIC QUAD FLAT PACK.
PR	PUBLIC RELATIONS.
PRI	PRIORITY MESSAGE (NTN).
PRISM	PAY RECORDS INPUT SYSTEM.
PROBE	PERSONNEL RECORDS ON-LINE & BATCH ENQUIRIES.
PROMISE	PLANNING RESOURCES MONITORING SYSTEM.
PROM	PROGRAMABLE READ ONLY MEMORY.
PROMS	PROBLEM MANAGEMENT SYSTEM.
PROSPER	PROJECT MANAGEMENT.
PROTIM	PLANNING RESOURCES TIMING SYSTEM.
PS	POWER STATION.
PSI	POUNDS PER SQUARE INCH.
PSR	PERMANENT SPEED RESTRICTION.
PSS	PACKET SWITCHED SERVICE.
PS&S	PASSENGER SYSTEMS & SERVICES.
PSB	PANEL/POWER SIGNAL BOX.
PSG	PRODUCTION/PROGRAM SUPPORT GROUP. (BRC)
PSI	PASSENGER SALES INFORMATION MANUAL.
PSO	PUBLIC SERVICE OBLIGATION.
PSP	PROBLEM SOLVING PROCESS.
PSTN	PUBLIC SWITCHED TELEPHONE NETWORK.
PT	PARCELS TERMINAL.
PTA	PASSENGER TRANSPORT/TRAIN AUTHORITY.
PTE	PASSENGER TRANSPORT EXECUTIVE.
PTN	PRIVATE TELECOMMUNICATIONS NETWORK.
PTO	PRINCIPAL TECHNICAL OFFICER.
PT&R	PROMOTION, TRANSFER AND REDUNDANCY.
PTR	PRIVILAGE TICKET REGULATIONS.
PTS	PERSONAL TRACK SAFETY (CERTIFICATE).
PTT	POCKET TIMETABLE.
PUBS	ELECTRONIC PUBLISHING SYSTEM.
PUMP	PLANNED UTILISATION OF MAINTENANCE PLANT.
PVHS	PARCELS VAN HOLDING SIDING.
PW	PARALLEL WING. (RAIL)
PW	PERMANENT WAY.
PWF	PRIVATE WAGON FEDERATION.
PWMA	PERMANENT WAY MACHINE ASSISTANT.
PWME	PERMANENT WAY MACHINE ENGINEER.
PWRA	PRIVATE WAGON REGISTRATION AGREEMENT.
PWSS	PERMANENT WAY SECTION SUPERVISOR.
Q&SS	QUALITY AND SAFETY SERVICES.
QA	QUALITY ASSURANCE.
QAT	QUALITY AT WORK.
QIT	QUALITY IMPROVEMENT TECHNIQUES/TEAM.
QLLC	QUALIFIED LOGICAL LINK CONTROL.
QR	QUAD ROYAL (POSTER SITE)
QTAM	QUEUED TELECOMMUNICATIONS ACCESS METHOD.
QTP	QUALITY THROUGH PEOPLE.
QTT	QUALITY THROUGH TEAMWORK.
R	RED SIGNAL.
R	REVERSE (POSITION OF POINTS).
RA	ROUTE AVAILABILITY.
RA	RIGHT AWAY.
RA	RECORDED ANNOUNCEMENT.
RACF	REPLACEMENT (FOR) ACF2
RACV	RESTRICTED APPLICATION CONTROL VALVE.
RADAR	RAILFREIGHT DISTRIBUTION ACCOUNTS RECEIVABLE SYSTEM.
RADIS	REPORTING AND ANALYSIS OF DELAY INFORMATION SYSTEM.
RADISH	REPORTING AND ANALYSIS OF DELAY INFORMATION SYSTEM: HISTORICAL
RAILFAIL	RAIL FAILURES.
RAILPLAN	RAIL PLANNING SYSTEM.
RAM	RANDOM-ACCESS MEMORY.
RAMDAC	RANDOM-ACCESS MEMORY DIGITAL-TO-ANALOGUE CONVERTER.
RAVERS	RAIL VEHICLE RECORDS SYSTEM.
RB	RULE BOOK.
RBR	RESTAURANT BUFFET, REFURBISH.
RCE	REGIONAL CIVIL ENGINEER.
RCH	RAILWAY CLEARING HOUSE.
RCH	RAILWAY CONVALESCENCE HOMES.
RCO	ROUTE/REGIONAL CONTROL OFFICE.
RCT	RAIL CONTAINER DEPOT.
RD	REST DAY.
RDW	REST DAY WORKED.
RE	RAILWAY EXECUTIVE.
RE	RUNNING EDGE. (THE FACE OF THE RAIL FROM WHICH THE GAUGE IS MEASURED)
RE	WITH REFERENCE TO.
REB	RE-LOCATABLE EQUIPMENT BUILDINGS.
RECP	RECEPTION SIDINGS.
RECSC	RAILWAY EXECUTIVE COMMITTEE STAFF COMMITTEE.
REM	REGIONAL ENERGY MANAGER.
REMFIS	RAIL MANCHE FINANCE INTEGRATED SYSTEM.
REN	RINGER EQUIVALENCE NUMBER.
RENFE	SPANISH NATIONAL RAILWAYS.
REPTA	RAIL EMPLOYEES PRIVILEDE TICKET ASSOCIATION.
RES	RAIL EXPRESS SYSTEMS (PREVIOUSLY RAIL EXPRESS PARCELS).
RESOTO	RAIL EXPRESS SYSTEMS ONE TOPS OFFICE.
RETB	RADIO ELECTRONIC TOKEN BLOCK.
REV	FOUND ON INTERNATIONAL VEHICLES TO SHOW OVERHALL DATE.
RF&PM	REGIONAL FINANCE AND PLANNING MANAGER.
RFB	BUFFET OPEN FIRST.
RFD	RAILFREIGHT DISTRIBUTION.
RFFSA	REDE FERROVIARIA FEDERAL S.A. (BRAZILIAN RAILWAY CO.)
RFI	RADIO FREQUENCY INTERFERENCE.
RFM	RESTAURANT FIRST - MODUAL.
RFO	REGIONAL FINANCE OFFICE.
RFO	RESTAURANT FIRST OPEN.
RFS	RAIL FREIGHT SERVICES ENGINEERING. (EX BREL)
RG	RED GREEN (CROSSING).
RGB	RED/GREEN/BLUE.
RHA	ROAD HAULAGE ASSOCIATION.
RHB	RHAETIAN RAILWAYS (SWITZERLAND).
RH	RIGHT HAND.
RHS	RECTANGULAR HOLLOW SECTION.
RHS	RIGHT HAND SIDE.
RI	RAILWAY INSPECTORATE.
RIC	REVENUE INITIALISATION CARTRIDGE.
RICS	ROYAL INSTITUTE OF CHARTERED SURVEYORS.
RID	REGULATIONS CONCERNING THE INTERNATIONAL CARRIAGE OF DANGEROUS GOODS BY ROAD.
RIDDOR	THE REPORTING OF INJURIES, DISEASES AND DANGEROUS OCCURANCES REGULATIONS.
RITA	RAILWAY INDUSTRY TECHNICAL ASSOCIATION.
RITC	RAILWAY INDUSTRY TRAINING COUNCIL.
RIV	REGULATIONS FOR INTERNATIONAL VEHICLES. (REGOLAMENTO INTERNAZIONALE VEICOLI)
RJE	REMOTE JOB ENTRY.
RJITC	RAILWAY JOINT INDUSTRIAL TRAINING COUNCIL.
RL	RELIEF LINE.
RLO	RESTAURANT LOUNGE OPEN.
RLP	RAIL LINK PROJECT.
RMB	RESTAURANT MINATURE BUFFET.
RMF	RAIL MANCHE FINANCE
RMFIS	RAIL MANCHE FINANCE INTEGRATED SYSTEM.
RMT	RAILWAY MARITIME AND TRANSPORT WORKERS UNION. (FORMERLY NUR)
RO	RECEIVE ONLY. (NTN PRINTER)
ROC	ROUTE OPERATIONS CONTROL.
ROM	READ-ONLY MEMORY.
ROM	REGIONAL OPERATIONS MANAGER.
ROMPS	RAIL OPERATIONS & MANAGEMENT PLANNING SYSTEM.
ROP	RATE OF PAY.
ROSCOS	ROLLING STOCK LEASING COMPANIES.
ROVERS	ROAD VEHICLE RECORDS SYSTEM.
RPI	REVENUE PROTECTION INSPECTOR.
RPM	REVOLUTIONS PER MINUTE.
RPOS	RETAIL POINT OF SALE.
RPS	RAIL PLANNING SYSTEM.
RPTSNC	RAILWAY PROFFESIONAL & TECHNICAL STAFF NATIONAL COUNCIL.
RR	REGIONAL RAILWAYS.
RRC	REGIONAL RAILWAYS CENTRAL.
RRNE	REGIONAL RAILWAYS NORTH EAST.
RRNW	REGIONAL RAILWAYS NORTH WEST.
RRWW	REGIONAL RAILWAYS WALES & WEST.
RR	STOPS TO RUN ROUND.
RS	RAILWAY SUPERVISOR.
RS	RECESSING SIDINGS.
RSC	RAILWAYS SAFETY CASE.
RSC	RAILWAYS STAFF CONFERENCE.
RSI	ROLLING STOCK INSPECTOR.
RSJC	RAILWAY STAFF JOINT COUNCIL.
RSL	ROLLING STOCK LIBRARY.
RSLVECOMAS	ROLLING STOCK LIBRARY VEHICLE CODE MASTER FILE.
RSNC	RAILWAY STAFF NATIONAL COUNCIL.
RSNT	RAILWAY STAFF NATIONAL TRIBUNAL.
RST	ROLLING STOCK TECHNICIAN.
RT	RAILTRACK.
RT	RETIMED.
RT&R	REDUNDANCY, TRANSFER AND RESETTLEMENT PROCEDURES.
RTC	RAILWAY TECHNICAL CENTRE.
RTC	REAL-TIME CLOCK.
RTM	REGIE DES TRANSPORTS MARITIMES. (BELGIAN FERRIES)
RTS	RAILWAY TRAINING SCHEME.
RTS	REFUSE TRANSFER STATION.
RUCC	RAIL USERS' CONSULTATIVE COMMITTEE.
RUG	RAILFREIGHT USERS GROUP.
RUO	RESTAURANT UNCLASSIFIED OPEN.
RVRS	RAIL VEHICLE RECORDS SYSTEM.
RWSSNC	RAILWAY WORKSHOP SUPERVISORY STAFF NATIONAL COUNCIL.
S&C	SETTLE & CARLISLE.
S&C	SWITCHES & CROSSINGS.
S&E	STOP & EXAMINE.
S&T	SIGNAL & TELECOMMUNICATIONS ENGINEERING.
S&TE	SIGNAL & TELECOMMUNICATIONS ENGINEER.
SAA	SYSTEMS APPLICATION ARCHITECTURE (IBM).
SAD	SYSTEM ABBREVIATED DIALLING.
SAD	SYSTEM ARCHITECTURE DIAGRAM.
SAFGABS	SYSTEM ANALYSIS FOR GRANT AID AND BUSINESS STUDIES.
SAMIN	SYSTEM ANALYSIS OF MANAGEMENT INFORMATION NEEDS.
SAMIS	S&T ESTIMATING SYSTEM.
SAMOS	SALES MONITORING SYSTEM.
SAMS	STORES ACCOUNTING MANAGEMENT SYSTEM.
SAPROC	SALES PROMOTIONAL CYCLE.
SATBUD	S&T BUDGETS.
SAU	SELF ACCOUNTING UNIT.
SB	SIGNAL BOX.
SBB	SWISS FEDERAL RAILWAYS.
SBS	SIGNAL BOX SIMPLIFIER.
SBS	STOPPED BY SIGNALS.
SC	SECTIONAL COUNCIL. (A) SALARIED GRADES, (B) FOOTPLATE STAFF, (C) CONCILIATION, (D) PW S&T & OLE, (E) SHIPPING.
SC	SOUTH CENTRAL.
SCAAS	STOCK CONTROL AND ACCOUNTS SYSTEM.
SCAMOS	STORES CONTROL & MONITORING ORDERING SYSTEM.
SCL	STANDARD CARRIAGE LENGTHS.
SCOC	STOCK CONTROL AND ORDERING CENTRE.
SCOTVEC	SCOTTISH VOCATIONAL EDUCATION COUNCIL.
SCR	SCOTRAIL AND NORTH OF NEWCASTLE (NFM).
SCSI	SMALL COMPUTER SYSTEM INTERFACE.
SD	SWITCH DIAMOND.
SDF	SCREEN DEFINITION FACILITY.
SDLC	SYNCHRONOUS DATA LINK CONTROL.
SDMM	SYSTEMS DEVELOPMENT METHODS MANUAL.
SDP	STATION DEPARTURE POSTERS.
SDR	STANDARD DAY RETURN (NFM).
SDR	SYSTEM DEVELOPMENT REQUEST.
SDRU	SUPER DATA RETRIEVAL UNIT.
SDS	SAFETY DATA SHEETS.
SDS	STANDARD DAY SINGLE (NFM).
SDS	STATEMENT OF DIVISION SYSTEM.
SDT	SCANNING DATA TERMINAL.
SDT	SUMMARY OF DAILY TRANSACTIONS (BOOKING OFFICE DAILY RECORD)
SE	SOUTH EASTERN.
SEMI	SEMI-AUTOMATIC SIGNAL.
SERPS	SPECIAL EARLY RETIREMENT PENSION SCHEME.
SERPS	STATE EARNINGS RELATED PENSION SCHEME.
SERVER	A NODE ON A LAN THAT ALLOWS OTHER NODES TO ACCESS ITS FACILITIES.
SF	SHUNTING FRAME.
SFL	SPECIFIC FAULT LIGHT.
SFU	SHADOW FRANCHISE UNIT.
SG	SPHEROIDAL GRAPHITE. (CAST IRON BASE PLATES)
SIG	SIGNAL.
SIMBIDS	SIMPLIFIED BI-DIRECTIONAL SIGNALLING.
SIMM	SINGLE IN-LINE MEMORY MODULE.
SIMPSCHED	SIMPLIFIED SCHEDULING PROGRAM.
SIN	SUBSTANCE IDENTIFICATION NUMBER.
SIPS	SIGNALLING INFRASTRUCTURE PERFORMANCE SYSTEM.
SIX FOOT	THE GAP BETWEEN TWO ADJACENT RUNNING LINES. (SEE TEN FOOT)
SJ	SWEDISH STATE RAILWAYS.
SJCMON	SPECIAL JOINT COMMITTEE ON MACHINERY OF NEGOTIATION.
SK	STANDARD CORRIDOR. (COACH)
SL	SHUNT LIMIT.
SL	SHUNT LOCOMOTIVE.
SL	SPECIAL LEAVE.
SLE	SLEEPER. (COACH)
SLEP	SLEEPER, PANTRY. (COACH)
SLK	SPEEDLINK.
SLUS	STANDARD LENGTH UINITS
SLW	SINGLE LINE WORKING.
SMART	SIGNAL MONITORING AND REPORTING TO TRUST.
SMC	STATION MANAGEMENT CENTRE.
SMITH	SIGNAL MAINTENANCE TESTERS HANDBOOK (S&T).
SN	SPECIAL NOTICE.
SNA	SYSTEMS NETWORK ARCHITECTURE (IBM).
SNCB	SOCIETE NATIONALE DES CHEMINS DE FER BELGES: BELGIAN STATE RAILWAYS.
SNCF	SOCIETY NATIONALE DES CHEMINS DE FER FRANCIS: FRENCH STATE RAILWAYS.
SNMP	SIMPLE NETWORK MANAGEMENT PROTOCOL.
SO	STANDARD OPEN. (COACH)
SOB	SWISS SOUTH EASTERN RAILWAY.
SOLD	SYSTEM FOR ON-LINE DEBITING.
SOLE	SAFETY OF LINE EXAMINATION.
SOOC	STOPPED OUT OF COURSE.
SOP	SHORT OF POWER.
SOP	SIGNING ON POINT.
SOR	STANDARD OPEN RETURN (NFM).
SOW	SITE OF WORK.
SOWC	SHOWING OCCUPIED WHEN CLEAR: WITHOUT CAUSE.
SPAD OR SPD	SIGNAL PASSED AT DANGER.
SPAMS	SECTOR PERFORMANCE ACCOUNTING AND MONITORING SYSTEM. (SUPERCEEDED BY AXIS)
SPC	SINGLE POWER CAR.
SPC	STATISTICAL PROCESS CONTROL.
SPC	STORED PROGRAM CONTROL. (BT TELEX)
SPECTRA	SPECIAL TRAFFIC NOTICES. (LMR)
SPM	SHIFT PRODUCTION MANAGER.
SPOOL	SIMULTANEOUS PERIPHERAL OPERATION ON-LINE.
SPORTIS	SUPER PORTABLE TICKET ISSUING SYSTEM.
SPOTIS	SUPER PASSENGER OPERATED TICKET ISSUING SYSTEM. (QUICKFARE)
SPT	SIGNAL POST TELEPHONE.
SQL	STRUCTURED QUERY LANGUAGE.
SRAM	STATIC RANDOM-ACCESS MEMORY.
SRMTS	SR MASTER TIMETABLE SYSTEM.
SS	SECTION SIDINGS.
SS	SINGLE SLIP.
SSA	STRUCTURED SYSTEMS ANALYSIS.
SSC	SIGNALLING SUB-COMMITTEE.
SSF	SPEED SENSORY FITTED.
SSI	SOLID STATE INTERLOCKING.
SSO	SPECIAL STOP ORDER.
SSP	STANDARD SIGNALLING PROCEDURES.
SSP	STATUTORY SICK PAY.
SSPLR	STATUTARY SICK PAY LOCAL RECORDING SYSTEM.
SSR	SUPERSAVER RETURN (NFM).
SSS	SUPERSAVER SINGLE (NFM).
S WAGONS	INTERNATIONAL WAGONS WITH A MAXIMUM SPEED OF 60 MPH.
SS WAGONS	INTERNATIONAL WAGONS WITH A MAXIMUM SPEED OF 75 MPH.
STABS	S&T AREA BUDGETING SYSTEM.
STAG	SIGNALLING, TELECOMMUNICATIONS AND GENERAL ENGINEERING.
STARS	SEALINK TRAVEL AND RESERVATION SYSTEM.
STATMUX	STATISTICAL MULTIPLEXER.
STD	SUBSCRIBER TRUNK DIALING.
STEELSURE	CONSIGNMENT MONITORING SYSTEM ON TOPS.
STF	STORE AND FORWARD (NTN).
STH	FORMER SOUTHERN REGION (NFM).
STIMPS	S&T PROGRAM THAT EXTRACTS IMPS DATA.
STN	SPECIAL TRAFFIC NOTICE.
STO	SENIOR TECHNICAL OFFICER.
STOCS	STORES CONTROLLER ORDERING CONTROL SYSTEM.
STOPS	S&T OUT-TURN PROCESSING SYSTEM.
STP	SHORT TERM PLANNING.
STRADS	SECTOR TRAFFIC DATA SYSTEM.
STS	STANDARD SINGLE (NFM).
STYX	S&T CO-ORDINATED SYSTEM.
SVGA	SUPER VIDEO GRAPHICS ARRAY.
SVR	SAVER RETURN (NFM).
SW	SOUTH WESTERN.
SWL	SAFE WORKING LOAD.
SWL	SOUTH WESTERN LINES.
SZ	SOLVERNSKE ZELENICE - SLOVENIAN RAILWAYS.
SZD	RUSSIAN STATE RAILWAYS.
T&A	TIME AND ATTENDANCE SYSTEM.
T&RS	TRACTION & ROLLING STOCK.
T&RSMD	TRACTION & ROLLING STOCK MAINTENANCE DEPOT.
TA	TERMINAL ADDRESS.
TA	TRAVEL AGENCY.
TAAC	TRAVEL AGENTS ACCOUNTING CENTRE (WATFORD).
TABS	TRADING ADVICE BUDGETING SYSTEM.
TAM	TRAVEL AGENTS MANUAL.
TAPS	TIME APPROPRIATION.
TAPSIS	TRAVEL AGENTS, PRIVATE SETTLEMENTS AND IRISH STATIONS SYSTEM.
TARDIS	TOPS ANCILLARY RETROSPECTIVE DATA INFORMATION SYSTEM.
TARE	THE WEIGHT OF AN EMPTY WAGON.
TAT	TRANSITIONAL AUTOMATED TICKET.
TAT	TASK ATTRIBUTE TIME. (TOPS SYSTEM)
TBA	TO BE ADVISED.
TBCF	TO BE CALLED FOR.
TBF	TOTAL BRAKE FORCE.
TBM	TIMING BY MICRO.
TBM	TRAINLOAD BUSINESS MANAGEMENT.
TBR	TIME BREAK RECALL. (USED ON PBX'S)
TBS	TALKED BY SIGNAL.
TBS	TRAILER BRAKE STANDARD.
TBSL	TRAILER BRAKE STANDARD, LAVATORY.
TC	TERMINAL COMPLEX.
TC	TRAILER COMPOSITE.
TC	TRAIN CREW.
TCA	TRACK CIRCUIT ACTUATORS.
TCAM	TELECOMMUNICATIONS ACCESS METHOD.
TCB	TRACK CIRCUIT BLOCK.
TCCU	TERMINAL CLUSTER CONTROL UNIT.
TCDD	TURKISH STATE RAILWAYS.
TCF	TRACK CIRCUIT FAILURE.
TCFD	TYNESIDE CENTRAL FREIGHT DEPOT.
TCI	TRAIN CREW INSPECTOR.
TCL	TRAILER COMPOSITE, LAVATORY.
TCL	TRAIN CREW LEADER (D) DRIVER, (G) GUARD.
TCOJ	GRANGESBURG-OXELSUNDS RAILWAY. (SWEDEN)
TCR	TRAIN CREW ROSTERING.
TCS	TRAIN CREW SUPERVISOR.
TCV	TARIF COMMUN VOYAGEUR.
TD	TRAIN DESCRIBERS.
TDC	TOPS DATA CONVERTOR
TDCC	TECHNICAL DATA CONTROL CENTRE.
TDM	TIME DIVISION MULTIPLEX.
TDM	TIME DEPENDANT MESSAGE. (TOPS)
TDQ	TRANSIENT DATA QUEUE.
TDU	TERMINAL DRIVER UNIT.
TEB	TELEPHONE ENQUIRY BUREAU.
TEE	TRANS EUROPEAN EXPRESS.
TEH	TICKET EXAMINER'S HANDBOOK.
TEN FOOT	THE GAP BETWEEN TWO ADJACENT PAIRS OF RUNNING LINES.
TERMINAL	AN ENTRY AND EXIT POINT FOR INFORMATION ON A NETWORK.
TESCOS	TRAIN ENGINEERING SERVICE UNITS.
TF	TRAILER FIRST (HST).
TFA	TRAIN FILE ADDRESS.
TFC	TELECOMMS FAULT CONTROL.
TFCS	TAX FREE CASH SUM.
TFM	THROUGH FARES MANUAL
TFT	THIN FILM TRANSISTOR.
TGS	TRAILER GUARD STANDARS (HST).
TGV	TRAIN A GRANDE VITESSE (SNCF HIGH SPEED TRAIN).
TIDES	TRAVEL INFORMATION DATA ENTRY SYSTEM.
TIMELORD	TIME RECORDING SYSTEM.
TIMEMASTER	TIME RECORDING SYSTEM.
TIMES	TIME INPUT RECORDING SYSTEM.
TIMREC	TIME RECORDING SYSTEM.
TIPLOC	TRAIN IN POSITION LOCATION.
TIPS	TELECOMMUNICATIONS INSTALLATION & PROCUREMENT SERVICE.
TIR	TICKET IRREGULARITY.
TIR	TRANSPORT INTERNATIONAL ROUTIER.
TIS	TICKET ISSUING SYSTEM.
TIS	TRACTION INTERLOCK SWITCH.
TLDFAS	TRAINLOAD FLOW ANALYSIS SYSTEM.
TLF	TRAINLOAD FREIGHT.
TMD (D)	TRACTION MAINTENANCE DEPOT (DIESEL).
TMD (E)	TRACTION MAINTENANCE DEPOT (ELECTRIC).
TMIS	TRACTION MOTOR ISOLATING SWITCH.
TML	TRANS MARCHE LINK
TMR	TOPS MODIFICATION REQUEST.
TMST	TRANS MARCHE SUPER TRAIN.
TMX	TYPED MESSAGE EXCHANGE (NTN).
TNC	TELECOMMUNICATIONS NETWORK CONTROL.
TO	TECHNICAL OFFICER.
TO	TOURIST OPEN STANDARD. (MK4 COACH)
TO	TRACTION OVERLOAD.
TO	TURN OUT.
TOA	TIME OF ARRIVAL.
TOC	TOPS ON-LINE CONTROL.
TOC	TRAIN OPERATING COMPANY.
TOD	TOURIST OPEN STANDARD. (MK4 COACH) (DISABLED TOILET)
TOD	TIME OF DEPARTURE.
TOE	TOURIST OPEN STANDARD. (MK4 COACH) (BUFFERS ONE END)
TOG	TOPS OPERATIONS GROUP.
TOPS	TOTAL OPERATIONS PROCESSING SYSTEM.
TOPS 2000	GRAPHICAL FRONT END FOR TOPS. (SYSTEM UNDER DEVELOPMENT)
TOPSCICS	TOPS + CUSTOMER INFORMATION CONTROL SYSTEM.
TOP2CICS	THIS IS WHERE THE FOLLOWING APPLICATIONS RESIDE: AVACS, AVI, GUARDS COUNT, RADIS, STEELSURE, EXPEDITE LINK & MULES.
TOP3CICS	THIS IS WHERE THE FOLLOWING APPLICATIONS RESIDE: TSIA, EDTA, MGRP & DIADS/EXT/PCD.
TOP4CICS	THIS IS WHERE THE FOLLOWING APPLICATIONS RESIDE: TRUST.
TOR	TERMINAL OWNING REGION.
TORR	TRAIN OPERATED ROUTE RELEASE.
TOU	TRAIN OPERATING UNIT.
TOWS	TRAIN OPERATED WARNING SYSTEM.
TP	TRANSACTION PROCESSING.
TP&SS	TRAIN PERFORMANCE & STATISTICS SYSTEM.
TPI	TRACTION AND PLANT INSPECTOR (M&EE).
TPI	TRACKS PER INCH.
TPO	TRAIN PLANNING OFFICE.
TPO	TRAVELLING POST OFFICE.
TPRLS	TEMPORARY PAY RELATED LUMP SUM.
TPS	TRAIN PLANNING SYSTEM.
TPV	THROUGH PIPED VEHICLE.
TPU	TRAIN PLANNING UNIT.
TQM	TOTAL QUALITY MANAGEMENT.
TRA	TOPS RESPONSIBILITY AREA.
TRACMAN	TRAIN CREW MANAGEMENT.
TRACS	TRANSIT RESERVATION AND CONTROLLED SCHEDULE.
TRAFIC	TRANSMISSION & RECEIPT OF ACCOUNTING FINANCIAL INFORMATION AND ITS CONSOLIDATION.
TRAINS	TRAINING RECORDS ADMIN. INFORMATION & NOMINATION SYSTEM.
TRAMM	TRACK RENEWAL AND MAINTENANCE MACHINE.
TRANSFESA	AN OPERATOR OF PRIVATLEY OWNED WAGONS.
TRAPS	TRAINLOAD RESOURSES AND PROFITABILITY SYSTEM.
TRB	TRAILER RESTAURANT FIRST BUFFET. (4O2 PASSENGER COACH)
TRFB	TRAILER RESTAURANT FIRST BUFFET. (4O7 PASSENGER COACH)
TRFK	TRAILER RESTAURANT FIRST KITCHEN. (PASSENGER COACH)
TRI	TRACTION ROLLING STOCK INSPECTOR.
TRS	TRACTION & ROLLING STOCK.
TRSB	TRAILER RESTAURANT STANDARD BUFFET. (PASSENGER COACH)
TRS	TRAIN READY TO START.
TRTS	TRAIN READY TO START INDICATOR.
TRSMD	TRACTION & ROLLING STOCK MAINTENANCE DEPOT.
TRUB	TRAILER RESTAURANT UNCLASSIFIED BUFFET.
TRUST	TRAIN RUNNING SYSTEM: TOPS.
TS	TRAILER STANDARD. (PASSENGER COACH)
TSC	TRACK SECTIONING CABIN.
TSD	TECHNICAL SERVICES DEPARTMENT.
TSDB	TRAIN SERVICE DATABASE.
TSG	TECHNICAL SUPPORT GROUP.
TSI	TRAIN SERVICE INFORMATION.
TSL	TRAILER STANDARD, LAVATORY. (PASSENGER COACH)
TSM	TECHNICAL SERVICES MANAGER.
TSO	TIME SHARE OPTION.
TSO	TOURIST STANDARD OPEN. (PASSENGER COACH)
TSO	TRAILER STANDARD OPEN. (HST)
TSOT	TOURIST STANDARD OPEN - TROLLEY. (PASSENGER COACH)
TSQ	TEMPORARY STORAGE QUEUE.
TSR	TEMPORARY SPEED RESTRICTION.
TSR	TERMINATE-AND-STAY-RESIDENT.
TSS	TELEPHONE SALES SERVICE.
TSSA	TRANSPORT SALARIED STAFFS ASSOCIATION.
TSU	TELEPHONE SALES UNIT.
TSU	TRANSPORT STUDIES UNIT.
TUCC	TRANSPORT USERS' CONSULTATIVE COMMITTEE.
TUPE	TRANSFER OF UNDERTAKINGS (PROTECTION OF EMPLOYMENT) REGS.
TWA	TRANSCONTINENTAL AND WESTERN AIR INC.
UAT	ULTRASONIC AXLE TEST.
UDL	UNIFORMLY DISTRIBUTED LOADING.
UG	UP GOODS
UF	UP FAST.
UFC	UNIFIED FAULT CONTROL (SIGNALLING).
UGL	UP GOODS LOOP.
UIC	UNION INTERNATIONAL CHEMIN DE FER. (INTERNATIONAL UNION OF RAILWAYS)
UMB	UPPER MEMORY BLOCK.
UML	UP MAIN LINE.
UPN	UNIQUE POST NUMBER.
UPS	UNINTERRUPTABLE POWER SUPPLY.
URL	UP RELIEF LINE.
US	UNSERVICABLE.
US	UP SIDINGS.
US	UP SLOW.
UTP	UNSHIELDED TWISTED PAIR.
UTU	ULTRASONIC TEST UNIT.
UVS	URGENT VEHICLE SHIPMENT.
VAT	VALUE ADDED TAX.
V	VOLT(S).
VDC	VOLT(S) DIRECT CURRENT.
VARI	VOICE ACTIVATED RECORDED INFORMATION.
VB	VACUUM BRAKE.
VCM	VINYL CHLORIDE MONOMER.
VCMS	VEHICLE COSTING AND MANAGEMENT SYSTEM.
VDU	VISUAL DISPLAY UNIT.
VECOMASS	VEHICLE MASTER RECORDS. (RSL)
VGA	VIDEO GRAPHICS ARRAY.
VHSDR	VERY HIGH SPEED DATA RING.
VIBT	VEHICLE INSPECTION AND BRAKE TEST.
VIS	VIGILANCE ISOLATION SWITCH.
VISION	VISUALISATION AND INTERACTIVE SIMULATION OF INFRASTRUCTURE AND OPERATIONS ON RAIL NETWORKS.
VLSI	VERY-LARGE-SCALE INTEGRATION.
VR	FINNISH RAILWAYS.
VRAM	VIDEO RANDOM-ACCESS MEMORY.
VSAT	VERY SMALL APERTURE TERMINALS.
VSOE	VENICE SIMPLON ORIENT EXPRESS.
VTAM	VIRTUAL TELECOMMUNICATIONS ACCESS METHOD.
VV	VERSATILE VIDEO.
VWP	VIDEO WORD PROCESSING.
W	WATT(S).
WA	WEST ANGLIA.
WAN	WIDE AREA NETWORK.
WAR	WORK AS REQUIRED.
WARS	WARRANT ACCOUNTING AND REVENUE SYSTEM.
WARS	WATERLOO AREA RESIGNALLING SYSTEM.
WASP	WORKS AND STRUCTURE PLANNING.
WBLO	WARNING BOARD LIGHTS OUT.
WCM	WORK CONTENT MINUTES.
WCML	WEST COAST MAIN LINE.
WCSG	WESTERN CONSTRUCTION SERVICES GROUP.
WEM	FORMER WESTERN REGION (NFM).
WH	WATT-HOUR(S).
WHS	WAGON HOLDING SIDING.
WI	WARNING INDICATOR.
WIMM	WHEEL IMPACT MONITORING MACHINE.
WIT	WORKSHOP IMPROVEMENT TEAM.
WKS	WORKS.
WON	WEEKLY OPERATING NOTICE.
WPC	WINDOW PERSONALITY CARTRIDGE.
WR	WESTERN REGION (FORMER).
WRCS	WAGON REPAIR CRIPPLE SIDING.
WRD	WAGON REPAIR DEPOT.
WS	WORK SHOP STAFF.
WSP	WHEEL SLIP PROTECTION.
WTN	WEEKLY TRAIN NOTICE.
WTR	WATER TEMPERATURE RELAY.
WTT	WORKING TIME TABLE.
WX	WESTBURY (WILTS).
XC	LOCOMOTIVE.
XDB	EXTENDED DATABASE PROGRAM.
XMM	EXTENDED MEMORY MANAGER.
XMS	EXTENDED MEMORY SPECIFICATION.
XS	EXCESS.
Y	YELLOW SIGNAL.
YD	YARD.
YY	DOUBLE YELLOW SIGNAL.
ZIF	ZERO INSERTION FORCE.
ACI	AUTOMATIC CODE INSERTION (USED ON IECC FOR AUTOMATIC REP NO CHANGE)
AIG	ACCESS IMPLEMENTATION GROUP
ALARP	AS LOW AS REASONABLY PRACTICABLE
AMU	(TRACK) ACCESS MANAGEMENT UNITS
ANATRAC	BRT PRODUCT NAME FOR ANALOGUE TELECOMMUNICATIONS CIRCUITS
AOCP	AUTOMATIC OPEN CROSSING REMOTELEY MONITORED
APLAN	REPLACEMENT TO PROTIM
APP	APPLICATIONS PROGRAM PROBLEM
ATR(E)	A.T.R. BY EXCEPTION
BFH	BUS FARE HOME
BRS	BUSSINESS ROUTE SECTION
BR1810	THE NORMAL PROTOCAL USED FOR COMMUNICATIONS FROM TRAIN DESCRIBERS
BS	BUSINESS SYSTEMS
COD	CENTRAL ORDINANCE DEPOT
DMLR	DEEMED MINUTES LATE ALLOCATED TO RAILTRACK
DMLT	DEEMED MINUTES LATE ALLOCATED TO OPERATOR (TOC/TOU)
DPM	DUTY PRODUCTION MANAGER
DSN	DAILY SUPPLEMENTARY NOTICE
EE&CS	ELECTRICAL ENGINEERING AND CONTROL SYSTEMS
EOT	END OF TRANSMISSION
EC4T	ELECTRIC CURRENT FOR TRACTION (FOR CALCULATING CHARGES)
ETE	ELECTRIC TRACTION ENGINEERS
FEP	FRONT END PROCESSOR
FP	FOOTPATH
GJT	GERERALISED JOURNEY TIME
IG	INFORMATION GENERATOR
IMI	IMPERIAL METALS INDUSTRIES
ITMIS	INTERLOGIC TRAIN MANAGEMENT INFORMATION SYSTEM
IMU	INFRASTRUCTURE MAINTANCE UNIT
IRU	INFRASTUCTURE RENEWALS UNIT
GSO	GROUP STANDARDS ORGANISATION
HAZOP	HAZARD OPERABILITY STUDY
HMRI	HER MAJESTYS RAILWAY INSPECORATE
HSWA	HEALTH AND SAFETY AT WORK ACT (1974)
LCR	LINE CLEAR RELEASE
LTP	LONG TERM PLAN (WTT TRAINS)
MAT	MATISSE AUTOMOTIVE TRANSPORT
MDR	MINUTES DELAY RAILTRACK
MDT	MIDLANDS DELAY OPERATOR (TOU/TOC)
MG	MANNED GATED CROSSING
MHSWR	MANAGEMENT OF HEALTH AND SAFETY AT WORK REGULATIONS 1992
MPD	MAJOR PROJECTS DIVISION
MBO	MANAGEMET BUY OUT
MSS	MINIMUM SERVICE STANDARD
MLS	MAXIMUM LINE SPEED
PMRD	PERFORMANCE MINUTES ALLOCATED TO RAILTRACK
MRE	MARGINAL REVENUE EFFECTS
MU	MULTIPLE UNIT
MWLB	MINATURE WARNING LIGHTS USER WORKED BARRIER CROSSING
MWLF	MINATURE WARNING LIGHTS USER WORKED FOOTPATH CROSSING
NIR	RAILTRACK NATIONAL INCIDENT ROOM
OPRAF	OFFICE OF PASSENGER RAIL FRANCHISING
OC	OPEN CROSSING
OCB	ON CALL BARRIER
PABS	PASSENGER ACCESS BILLING SYSTEM
PDFH	PASSANGER DEMAND FORECASTING HANDBOOK
PMRD	PERFORMANCE MINUTES RAILTRACK DELAY
PMTD	PERFORMANCE MINUTES OPERATOR DELAY
PROM	PROBLEM MANAGEMENT SYSTEM (USED BY NETWORK CONTROL)
PPTOM	PENCE PER TONNE MILE (FOR CALCULATING CHARGES)
PPTRM	PENCE PER TRAIN MILE (FOR CALCULATING CHARGES)
PREG	PERFORMANCE REGIME WORKING GROUP (SCHEDULE 8)
PI	PASSENGER INFORMATION
PIP	PERIPHERAL INTERCHANGE PACKAGE
PQQ	PRE QUALIFICATION QUESTIONAIRES
RACES	RAILTRACK GENERAL LEGER SYSTEM
RAFS	RAILTRACK FREIGHT SYSTEM
RAIDS	RAILTRACK ACCOUNTS RECEIVABLE SYSTEM
RIAC	RAILWAY INDUSTRY ADVISORY COMMITTE
RTIS	RAILTRACK INFORMATION SYSTEMS
ROSCO	ROLLING STOCK LEASING COMPANYS (EVERSHOLT,ANGEL AND PORTERBROOK)
RSP	RAIL SETTLEMENT PLAN
S&SD	RAILTRACKS SAFETY AND STANDARDS DIRECTORATE
SCALA	RAILTRACK FINANCIAL AND PROCUREMENT SYSTEM
SDP	SEVERE DISRUPTION PAYMENT
SDT	SERVERE DISRUPTION THRESHOLD
SIPS	STANDARD INFRASTRUCTURE PERFORMANCE SCHEME
SIS	STAFF INFORMATION SYSTEM
SIVS	STAFF INFORMATION VIDEO SYSTEM
SLA	SERVICE LEVEL AGREEMENT
SSG	SYSTEMS STEERING GROUP
SVTD	SMALL VAUGHANS TRAIN DESCRIBER
TOHD	TRAIN OPERATIONS HELP DESK
TAM	TRACK ACCESS MANAGERS
TESCO	TRAIN ENGINEERING SERVICES COMPANY
TLA	THREE LETTER ABBREVIATION
TMOB	TRAINMAN OPERATED BARRIER CROSSING
TMOG	TRAINMAN OPERATED GATED CROSSING
TRAMM	TRACK REPAIR AND MAINTENANCE MACHINE
TSC	TRAIN SERVICE CODE (FORMER PROFIT CENTRE / BATS CODES)
TMIS	TRAIN MOVEMENT INFORMATION SYSTEM
TRU	TRACK RENEWALS UNIT
TVFEP	TRENT VALLEY FRONT END PROCESSOR
UW	USER WORKED CROSSING
UWB	USER WORKED BARRIERS
UWG	USER WORKED GATES
UWBT	USER WORKED BARRIER TELEPHONE
UWGT	USER WORKED GATES TELEPHONE
VOL	VALUE OF LIFE
WCMLDCL	WEST COAST MAIN LINE DEVELOPMENT COMPANY
WTTID	WORKING TIME TABLE (TRAIN) IDENTITY
WEN	WEEKLY ENGINEERING NOTICE
WSF	WRONG SIDE FAILURE
VSTP	VERY SHORT TERM PLAN (CONTROL SPECIALS)
UAT	USER ACCEPTANCE TEST(ING)
ZCM	ZONAL COMMERCIAL MANAGERS
ZPM	ZONAL PRODUCTION MANAGERS